Imidazole and triazole containing bicyclic compounds as jak inhibitors

ABSTRACT

or a pharmaceutically-acceptable salt thereof, wherein the variables are defined in the specification, that are inhibitors of JAK kinases, particularly JAK3. The invention also provides pharmaceutical compositions comprising such compounds, and methods of using such compounds to treat gastrointestinal and other inflammatory diseases.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/795,699, filed on Jan. 23, 2019, the disclosure of which isincorporated herein by reference in its entirety.

BACKGROUND Field

The invention is directed to imidazole and triazole containing bicycliccompounds useful as JAK kinase inhibitors and more particularly as JAK3inhibitors that are selective for JAK3 over other members of the JAKkinase family such as JAK1, JAK2 and TYK2. The invention is alsodirected to pharmaceutical compositions comprising such compounds, andmethods of using such compounds to treat inflammatory diseases.

State of the Art

Ulcerative colitis is a chronic inflammatory disease of the colon. Thedisease is characterized by inflammation and ulceration of the mucosallayer of the rectum and the large intestine. Common symptoms includediarrhea, bloody stools, and abdominal pain. The clinical course isintermittent, marked by alternating periods of exacerbation andremission. Incidence seems to be greater in developed than in developingcountries. An estimated 1.2 million people in major industrializedcountries suffer from ulcerative colitis and the numbers are expected toincrease along with population growth. Patients with ulcerative colitisare at an increased risk of developing colorectal cancer (e.g., Daneseet al. N Engl J Med, 2011, 365, 1713-1725). Although there exists avariety of therapeutic options to promote and maintain remission ofulcerative colitis (UC) in patients, none is ideal. There remains anunmet medical need for an effective therapy to promote and maintainremission of moderate to severe UC without the safety concerns resultingfrom chronic, systemic immunosuppression.

Although the precise pathogenesis of UC is unclear, it is apparent thatproinflammatory cytokines play a pivotal role in the immunologicalresponse (Strober et al., Gastroenterol, 2011, 140, 1756-1767). Many ofthe proinflammatory cytokines most commonly elevated in UC (e.g., IL-4,IL-6, IL-13, IL-15, IL-23, IL-24, IFNγ and leptin), rely on the JAKfamily of tyrosine kinases (i.e., JAK1, JAK2, JAK3 and TYK2) for signaltransduction.

Inhibition of the JAK3 enzyme blocks the signaling of many keypro-inflammatory cytokines. Thus JAK3 inhibitors are likely to be usefulin the treatment of ulcerative colitis and other gastrointestinalinflammatory diseases such as Crohn's disease and immune checkpointinhibitor induced colitis. JAK3 inhibitors are also likely to be usefulfor the treatment of inflammatory skin diseases such as atopicdermatitis and inflammatory respiratory disorders such as allergicrhinitis, asthma, and chronic obstructive pulmonary disease (COPD). Inaddition, JAK3 inhibitors may also be useful in the treatment of manyocular diseases for which inflammation plays a prominent role such asuveitis, diabetic retinopathy, diabetic macular edema, dry eye disease,age-related macular degeneration, retinal vein occlusion (RVO) andatopic keratoconjunctivitis.

Selectivity for JAK3 over JAK1 is anticipated to be beneficial as thereis evidence that JAK3 selectivity allows sparing of potentiallybeneficial cytokines such as IL-10 which has been involved in mucosalhealing, IL-22 which is involved in mucus barrier protection andepithelial regeneration, and IL-6 which is involved in the proliferationof intestinal epithelial cells. Selectivity for JAK3 over JAK2 alsoallows sparing of erythropoietin (EPO) and thrombopoietin (TPO)signaling. Therefore, it would be desirable to provide new compoundswhich are selective JAK3 inhibitors over other members of the JAK kinasefamily such as JAK1, JAK2 and TYK2.

Finally, due to the modulating effect of the JAK/STAT pathway on theimmune system, systemic exposure to JAK inhibitors may have an adversesystemic immunosuppressive effect. It would be desirable, therefore, toprovide new JAK3 inhibitors which have their effect at the site ofaction without significant systemic effects. In particular, for thetreatment of gastrointestinal inflammatory diseases, such as ulcerativecolitis, it would be desirable to provide new JAK3 inhibitors which canbe administered orally and achieve therapeutically relevant exposure inthe gastrointestinal tract with minimal systemic exposure. For skindiseases, it would be desirable to provide new JAK3 inhibitors thatcould be administered topically to the skin with minimal systemicexposure.

Therefore, it would be desirable to provide new compounds which areselective JAK3 inhibitors over other members of the JAK kinase familysuch as JAK1, JAK2 and TYK2, and have minimal systemic exposure.

SUMMARY

In one aspect, the invention provides novel compounds having activity asJAK kinase inhibitors and more particularly as JAK3 inhibitors.

Accordingly, the invention provides a compound of formula (I):

or a pharmaceutically acceptable salt thereof, wherein

X¹ and X² are each independently selected from N and CH;

is selected from the group consisting of

R^(a), R^(b), R^(c), and R^(f) are each independently selected from thegroup consisting of H and C₁₋₃ alkyl;

R^(d), R^(e), R^(g), R^(h), R^(i), R^(j), R^(l), R^(m), R^(n) and R^(o)are each independently selected from the group consisting of H and C₁₋₃alkyl wherein the C₁₋₃ alkyl group may be optionally substituted with 1to 3 halogens;

A is selected from the group consisting of

(a) a 4 to 8 membered monocyclic heterocyclic group containing onenitrogen atom and optionally containing one additional heteroatomselected from N, S, S(O)₂ and O, and

(b) a 6 to 10 membered multicyclic heterocyclic group containing onenitrogen atom and optionally containing one additional heteroatomselected from N, S, S(O)₂ and O,

wherein L is linked to a carbon atom in A and A is optionallysubstituted with 1 to 3 R^(k) groups;

each R^(k) is independently selected from the group consisting of F, CN,C₁₋₃ alkoxy, and C₁₋₃ alkyl, wherein the C₁₋₃ alkyl group may beoptionally substituted with OH, OMe or 1 to 3 halogens;

R¹ is selected from the group consisting of

wherein R^(p) and R^(q) are each independently selected from the groupconsisting of H, C₃₋₅ cycloalkyl and C₁₋₆ alkyl;

R² is selected from the group consisting of H, Cl, OMe, Me and F;

R³ is selected from the group consisting of H, Me, Et, CF₃, OMe, and F;

R⁴ is selected from the group consisting of H, Me, OMe, Cl, and F; and

R⁵ is selected from the group consisting of H, Me, Et, and F.

The invention also provides a pharmaceutical composition comprising acompound of the disclosure, or a pharmaceutically acceptable saltthereof, and a pharmaceutically-acceptable carrier.

The invention also provides a method of treating a gastrointestinalinflammatory disease in a mammal, the method comprising administering tothe mammal a compound of the disclosure, or a pharmaceuticallyacceptable salt thereof, or a pharmaceutical composition of thedisclosure.

The invention also provides a method of treating inflammatory diseasesor disorders of the skin in a mammal, the method comprising applying acompound of the disclosure, or a pharmaceutically acceptable saltthereof, or a pharmaceutical composition of the disclosure to the skinof the mammal.

The invention also provides a method of treating cutaneous T-celllymphoma in a mammal, the method comprising applying a pharmaceuticalcomposition comprising a compound of the disclosure, or apharmaceutically acceptable salt thereof, to the skin of the mammal.

The invention also provides a compound of the disclosure or apharmaceutically acceptable salt thereof, as described herein for use inmedical therapy, as well as the use of a compound of the disclosure, ora pharmaceutically acceptable salt thereof, in the manufacture of aformulation or medicament for treating a gastrointestinal inflammatorydisease, or an inflammatory disease of the skin in a mammal.

DETAILED DESCRIPTION

Among other aspects, the invention provides JAK kinase inhibitors offormula (I) which are selective for JAK3 over other members of the JAKkinase family such as JAK1, JAK2 and TYK2, andpharmaceutically-acceptable salts thereof.

In one aspect, the invention provides compounds having activity as JAKkinase inhibitors, particularly as JAK3 kinase inhibitors.

Accordingly, the invention provides a compound of formula (I):

or a pharmaceutically acceptable salt thereof, wherein

X¹ and X² are each independently selected from N and CH;

is selected from the group consisting of

R^(a), R^(b), R^(c), and R^(f) are each independently selected from thegroup consisting of H and C₁₋₃ alkyl;

R^(d), R^(e), R^(g), R^(h), R^(i), R^(j), R^(l), R^(m), R^(n) and R^(o)are each independently selected from the group consisting of H and C₁₋₃alkyl wherein the C₁₋₃ alkyl group may be optionally substituted with 1to 3 halogens;

A is selected from the group consisting of

(a) a 4 to 8 membered monocyclic heterocyclic group containing onenitrogen atom and optionally containing one additional heteroatomselected from N, S, S(O)₂ and O, and

(b) a 6 to 10 membered multicyclic heterocyclic group containing onenitrogen atom and optionally containing one additional heteroatomselected from N, S, S(O)₂ and O,

wherein L is linked to a carbon atom in A and A is optionallysubstituted with 1 to 3 R^(k) groups;

each R^(k) is independently selected from the group consisting of F, CN,C₁₋₃ alkoxy, and C₁₋₃ alkyl, wherein the C₁₋₃ alkyl group may beoptionally substituted with OH, OMe or 1 to 3 halogens;

R¹ is selected from the group consisting of:

wherein R^(p) and R^(q) are each independently selected from the groupconsisting of H, C₃₋₅ cycloalkyl and C₁₋₆ alkyl;

R² is selected from the group consisting of H, Cl, OMe, Me and F;

R³ is selected from the group consisting of H, Me, Et, CF₃, OMe, and F;

R⁴ is selected from the group consisting of H, Me, OMe, Cl, and F; and

R⁵ is selected from the group consisting of H, Me, Et, and F.

In some embodiments, the compound has the Formula (II):

In some embodiments, the compound has the Formula (III):

In some embodiments, the compound has the Formula (IV):

In some embodiments, R¹ is selected from the group consisting of:

In some embodiments, R¹ is

In some embodiments, A is selected from the group consisting ofazetidine, pyrrolidine, piperidine, 2-azaspiro[3.3]heptane, andnortropane, wherein A is optionally substituted with 1 to 3 R^(k)groups. In some embodiments, A is selected from the group consisting ofazetidine and piperidine, wherein A is optionally substituted with 1 to3 R^(k) groups. In some embodiments, A is an azetidine optionallysubstituted with 1 to 3 R^(k) groups. In some embodiments, A is apiperidine optionally substituted with 1 to 3 R^(k) groups.

In some embodiments,

is selected from the group consisting of

In some embodiments,

is selected from the group consisting of

In some embodiments,

is selected from the group consisting of:

In some embodiments

is selected from the group consisting of:

In some embodiments,

is selected from the group consisting of:

In some embodiments,

is selected from the group consisting of:

In some embodiments,

is selected from the group consisting of:

is selected from the group consisting of

R¹ is

and

A is selected from the group consisting of azetidine and piperidine,wherein A is optionally substituted with 1 or 2 R^(k) groups, whereineach R^(k) is independently selected from the group consisting of methyland fluoro.

-   -   In some embodiments, the invention provides a compound selected        from the group consisting of:

or pharmaceutically acceptable salts thereof.

The invention also provides a pharmaceutical composition comprising acompound of the disclosure, or a pharmaceutically acceptable saltthereof, and a pharmaceutically-acceptable carrier. In some embodiments,the pharmaceutical composition further comprises one or more othertherapeutic agents. In some embodiments, the one or more othertherapeutic agent is useful for treating a gastrointestinal inflammatorydisease, an inflammatory disease of the skin, an inflammatory disease ofthe lungs or an inflammatory disease of the eye. In some embodiments,the one or more other therapeutic agent is useful for treating agastrointestinal inflammatory disease. In some embodiments thegastrointestinal inflammatory disease is ulcerative colitis. In someembodiments the gastrointestinal inflammatory disease is Crohn'sdisease. In some embodiments the gastrointestinal inflammatory diseaseis celiac disease.

Furthermore, some compounds may sometimes exist in tautomeric forms. Itwill be understood that although structures are shown, or named, in aparticular form, the invention also includes the tautomer thereof. Also,some compounds may sometimes exist in atropoisomeric forms. It will beunderstood that although structures are shown in a particular form, theinvention also includes the corresponding atropoisomeric forms thereof.

The compounds of the invention may contain one or more chiral centersand therefore, such compounds (and intermediates thereof) can exist asracemic mixtures; scalemic mixtures; pure stereoisomers (i.e.,enantiomers or diastereomers); stereoisomer-enriched mixtures and thelike. Chiral compounds shown or named herein without a definedstereochemistry at a chiral center are intended to include any or allpossible stereoisomer variations at the undefined stereocenter unlessotherwise indicated. The depiction or naming of a particularstereoisomer means the indicated stereocenter has the designatedstereochemistry with the understanding that minor amounts of otherstereoisomers may also be present unless otherwise indicated, providedthat the utility of the depicted or named compound is not eliminated bythe presence of another stereoisomer.

This invention also includes isotopically-labeled compounds of thedisclosure, for example isotopically-labeled compounds of formula (I),(II), (III), (IV), i.e., compounds of the disclosure and compounds offormula (I), (II), (III), (IV), where one or more atom has been replacedor enriched with an atom having the same atomic number but an atomicmass different from the atomic mass that predominates in nature.Examples of isotopes that may be incorporated into a compounds of thedisclosure and a compound of formula (I), (II), (III), (IV), include,but are not limited to, ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹³N, ¹⁵N, ¹⁵O, ¹⁷O, ¹⁸O,³⁵S, and ¹⁸F. Of particular interest are compounds of the disclosure andcompounds of formula (I), (II), (III), (IV), enriched in tritium orcarbon-14, which compounds can be used, for example, in tissuedistribution studies. Also of particular interest are compounds of thedisclosure and compounds of formula (I), (II), (III), (IV), enriched indeuterium especially at a site of metabolism, which compounds areexpected to have greater metabolic stability. Additionally, ofparticular interest are compounds of the disclosure and compounds offormula (I), (II), (III), (IV), enriched in a positron emitting isotope,such as ¹¹C, ¹⁸F, ¹⁵O and ¹³N, which compounds can be used, for example,in Positron Emission Tomography (PET) studies.

Definitions

When describing this invention including its various aspects andembodiments, the following terms have the following meanings, unlessotherwise indicated.

The term “alkyl” means a monovalent saturated hydrocarbon group whichmay be linear or branched or combinations thereof. Unless otherwisedefined, such alkyl groups typically contain from 1 to 10 carbon atoms.Representative alkyl groups include, by way of example, methyl (Me),ethyl (Et), n-propyl (n-Pr) or (nPr), isopropyl (i-Pr) or (iPr), n-butyl(n-Bu) or (nBu), sec-butyl, isobutyl, tert-butyl (t-Bu) or (tBu),n-pentyl, n-hexyl, 2,2-dimethylpropyl, 2-methylbutyl, 3-methylbutyl,2-ethylbutyl, 2,2-dimethylpentyl, 2-propylpentyl, and the like.

The term “haloalkyl” refers to an alkyl group, as defined above, that issubstituted by one or more halogen, e.g., trifluoromethyl,difluoromethyl, trichloromethyl, 2,2,2 trifluoroethyl, 1,2difluoroethyl, 3 bromo 2 fluoropropyl, 1,2 dibromoethyl, and the like.

When a specific number of carbon atoms are intended for a particularterm, the number of carbon atoms is shown preceding the term. Forexample, the term “C₁₋₃alkyl” means an alkyl group having from 1 to 3carbon atoms wherein the carbon atoms are in any chemically-acceptableconfiguration, including linear or branched configurations.

The term “alkoxy” means the monovalent group —O-alkyl, where alkyl isdefined as above. Representative alkoxy groups include, by way ofexample, methoxy, ethoxy, propoxy, butoxy, and the like.

The term “cycloalkyl” means a monovalent saturated carbocyclic groupwhich may be monocyclic or multicyclic. Unless otherwise defined, suchcycloalkyl groups typically contain from 3 to 10 carbon atoms.Representative cycloalkyl groups include, by way of example, cyclopropyl(cPr), cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl,adamantyl, and the like.

The term “heterocycle”, “heterocyclic”, or “heterocyclic ring” means asaturated or partially unsaturated cyclic non-aromatic group, havingfrom 3 to 10 total ring atoms, wherein the ring contains from 2 to 9carbon ring atoms and from 1 to 4 ring heteroatoms selected fromnitrogen, oxygen, and sulfur. Heterocyclic groups may be monocyclic ormulticyclic (i.e., fused, spiro or bridged). When the heterocyclic groupis multicyclic, at least one but not necessarily all of the cyclicgroups contains a heteroatom. Representative heterocyclic groupsinclude, by way of example, pyrrolidinyl, piperidinyl, piperazinyl,imidazolidinyl, morpholinyl, thiomorpholyl, indolin-3-yl,2-imidazolinyl, tetrahydropyranyl, 1,2,3,4-tetrahydroisoquinolin-2-yl,quinuclidinyl, 7-azanorbomanyl, nortropanyl, and the like, where thepoint of attachment is at any available carbon or nitrogen ring atom.Where the context makes the point of attachment of the heterocyclicgroup evident, such groups may alternatively be referred to as anon-valent species, i.e. pyrrolidine, piperidine, piperazine, imidazole,tetrahydropyran etc.

The term “therapeutically effective amount” means an amount sufficientto effect treatment when administered to a patient in need of treatment.

The term “treatment” as used herein means the treatment of a disease,disorder, or medical condition (such as a gastrointestinal inflammatorydisease), in a patient, such as a mammal (particularly a human) whichincludes one or more of the following:

(a) preventing the disease, disorder, or medical condition fromoccurring, i.e., preventing the reoccurrence of the disease or medicalcondition or prophylactic treatment of a patient that is pre-disposed tothe disease or medical condition;

(b) ameliorating the disease, disorder, or medical condition, i.e.,eliminating or causing regression of the disease, disorder, or medicalcondition in a patient, including counteracting the effects of othertherapeutic agents;

(c) suppressing the disease, disorder, or medical condition, i.e.,slowing or arresting the development of the disease, disorder, ormedical condition in a patient; or

(d) alleviating the symptoms of the disease, disorder, or medicalcondition in a patient.

The term “pharmaceutically acceptable salt” means a salt that isacceptable for administration to a patient or a mammal, such as a human(e.g., salts having acceptable mammalian safety for a given dosageregime). Representative pharmaceutically acceptable salts include saltsof acetic, ascorbic, benzenesulfonic, benzoic, camphorsulfonic, citric,ethanesulfonic, edisylic, fumaric, gentisic, gluconic, glucoronic,glutamic, hippuric, hydrobromic, hydrochloric, isethionic, lactic,lactobionic, maleic, malic, mandelic, methanesulfonic, mucic,naphthalenesulfonic, naphthalene-1,5-disulfonic,naphthalene-2,6-disulfonic, nicotinic, nitric, orotic, pamoic,pantothenic, phosphoric, succinic, sulfuric, tartaric, p-toluenesulfonicand xinafoic acid, and the like.

The term “amino-protecting group” means a protecting group suitable forpreventing undesired reactions at an amino nitrogen. Representativeamino-protecting groups include, but are not limited to, formyl; acylgroups, for example alkanoyl groups, such as acetyl andtri-fluoroacetyl; alkoxycarbonyl groups, such as tert-butoxycarbonyl(Boc); arylmethoxycarbonyl groups, such as benzyloxycarbonyl (Cbz) and9-fluorenylmethoxycarbonyl (Fmoc); arylmethyl groups, such as benzyl(Bn), trityl (Tr), and 1,1-di-(4′-methoxyphenyl)methyl; silyl groups,such as trimethylsilyl (TMS), triisopropylsiliyl (TIPS),tert-butyldimethylsilyl (TBS or TBDMS),[2-(trimethylsilyl)-ethoxy]methyl (SEM); and the like. Numerousprotecting groups, and their introduction and removal, are described inT. W. Greene and P. G. M. Wuts, Protecting Groups in Organic Synthesis,Third Edition, Wiley, New York

General Synthetic Procedures

Compounds of this disclosure, and intermediates thereof, can be preparedaccording to the following general methods and procedures usingcommercially-available or routinely-prepared starting materials andreagents. The substituents and variables (e.g., A, X¹, X², R¹, R², R³,R⁴, R⁵ etc.) used in the following schemes have the same meanings asthose defined elsewhere herein unless otherwise indicated. Additionally,compounds having an acidic or basic atom or functional group may be usedor may be produced as a salt unless otherwise indicated (in some cases,the use of a salt in a particular reaction will require conversion ofthe salt to a non-salt form, e.g., a free base, using routine proceduresbefore conducting the reaction).

Although a particular embodiment of the present invention may be shownor described in the following procedures, those skilled in the art willrecognize that other embodiments or aspects of the present invention canalso be prepared using such procedures or by using other methods,reagents, and starting materials known to those skilled in the art. Inparticular, it will be appreciated that compounds of the disclosure maybe prepared by a variety of process routes in which reactants arecombined in different orders to provide different intermediates en routeto producing final products.

A general method of preparing final compounds of the disclosure whereinL is selected from:

is illustrated in Scheme 1.

Starting material P1, where R^(x) and R^(y) are halogens which may bethe same or different, is reacted with P2 to give P3.

P2 may be:

where R^(z) is an amino-protecting group, for example Boc. In this case,P2 is deprotonated with a base such as NaH or KHMDS (potassiumhexamethyldisilazide) and reacted with P1 to give P3, or P1 and P2 arecombined in presence of a base, such as Cs₂CO₃ under heating to give P3.

Alternatively, P2 may be:

where R^(z) is an amino-protecting group, for example Boc. In this case,P2 is reacted with P1 under Buchwald coupling conditions such as in thepresence of Pd(0) and a base to give P3. Alternatively, P2 is reactedwith P1 in presence of a base such as DIPEA, under heat if necessary, togive P3.

Alternatively, P2 may be:

where R^(z) is an amino-protecting group, for example Boc. In this case,P2 is reacted with P1 in presence of Pd(0), 9-BBN and a base to form P3.

P3 is coupled with boronic acid P4 through a Suzuki coupling in presenceof Pd(0) and a base to give P5. P5 is deprotected to give P6 (when R^(z)is Boc, deprotection can be conducted in the presence of a strong acidsuch as TFA or HCl). Finally, P6 is derivatized into an amide by amidecoupling (reaction with an acid in presence of a coupling agent such asHATU or hydroxybenzotriazole (HOBT)) or reaction with an acyl chloridein presence of a base such as Hunig's base.

In this reaction scheme, the order of the reactions may be modified. Forexample the Suzuki coupling may be conducted before the introduction ofthe portion containing the A ring.

The sulfonyl linker can be obtained by oxidizing the correspondingsulfide, for example with oxone and basic alumina.

Accordingly, in a method aspect, the disclosure provides a method forpreparing a compound of formula (I) or a pharmaceutically acceptablesalt thereof,

the method comprising:

reacting a compound of formula:

with

(i) Cl—R¹, or

(ii) HO—R¹

wherein R¹, R², R³, R⁴, R⁵, X¹, X², L and A are as defined above, and

optionally forming a pharmaceutically-acceptable salt to provide acompound of formula (I), or a pharmaceutically acceptable salt thereof.

In separate and distinct aspects, the disclosure provides a compound offormula:

wherein the variables take any of the values described above.

Pharmaceutical Compositions

The compounds of the disclosure and pharmaceutically-acceptable saltsthereof are typically used in the form of a pharmaceutical compositionor formulation. Such pharmaceutical compositions may be administered toa patient by any acceptable route of administration including, but notlimited to, oral, topical (including transdermal), rectal, nasal,inhaled, and parenteral modes of administration.

Accordingly, in one of its composition aspects, the invention isdirected to a pharmaceutical composition comprising apharmaceutically-acceptable carrier or excipient and a compound offormula (I), (II), (III), or (IV), or a pharmaceutically-acceptable saltthereof. Optionally, such pharmaceutical compositions may contain othertherapeutic and/or formulating agents if desired. When discussingcompositions and uses thereof, the “compound of the invention” or“compound of the disclosure” may also be referred to herein as the“active agent”. As used herein, the term “compound(s) of the disclosure”is intended to include all compounds encompassed by formula (I), (II),(III), and (IV), and pharmaceutically-acceptable salts thereof.

The pharmaceutical compositions of the disclosure typically contain atherapeutically effective amount of a compound of the disclosure. Thoseskilled in the art will recognize, however, that a pharmaceuticalcomposition may contain more than a therapeutically effective amount,i.e., bulk compositions, or less than a therapeutically effectiveamount, i.e., individual unit doses designed for multiple administrationto achieve a therapeutically effective amount.

Typically, such pharmaceutical compositions will contain from about 0.1to about 95% by weight of the active agent; including from about 5 toabout 70% by weight of the active agent.

Any conventional carrier or excipient may be used in the pharmaceuticalcompositions of the invention. The choice of a particular carrier orexcipient, or combinations of carriers or excipients, will depend on themode of administration being used to treat a particular patient or typeof medical condition or disease state. In this regard, the preparationof a suitable pharmaceutical composition for a particular mode ofadministration is well within the scope of those skilled in thepharmaceutical arts. Additionally, the carriers or excipients used inthe pharmaceutical compositions of this invention arecommercially-available. By way of further illustration, conventionalformulation techniques are described in Remington: The Science andPractice of Pharmacy, 20th Edition, Lippincott Williams & White,Baltimore, Md. (2000); and H. C. Ansel et al., Pharmaceutical DosageForms and Drug Delivery Systems, 7th Edition, Lippincott Williams &White, Baltimore, Md. (1999).

Representative examples of materials which can serve as pharmaceuticallyacceptable carriers include, but are not limited to, the following:sugars, such as lactose, glucose and sucrose; starches, such as cornstarch and potato starch; cellulose, such as microcrystalline cellulose,and its derivatives, such as sodium carboxymethyl cellulose, ethylcellulose and cellulose acetate; powdered tragacanth; malt; gelatin;talc; excipients, such as cocoa butter and suppository waxes; oils, suchas peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil,corn oil and soybean oil; glycols, such as propylene glycol; polyols,such as glycerin, sorbitol, mannitol and polyethylene glycol; esters,such as ethyl oleate and ethyl laurate; agar; buffering agents, such asmagnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-freewater; isotonic saline; Ringer's solution; ethyl alcohol; phosphatebuffer solutions; and other non-toxic compatible substances employed inpharmaceutical compositions.

Pharmaceutical compositions are typically prepared by thoroughly andintimately mixing or blending the active agent with apharmaceutically-acceptable carrier and one or more optionalingredients. The resulting uniformly blended mixture can then be shapedor loaded into tablets, capsules, pills and the like using conventionalprocedures and equipment.

The pharmaceutical compositions of the disclosure are preferablypackaged in a unit dosage form. The term “unit dosage form” refers to aphysically discrete unit suitable for dosing a patient, i.e., each unitcontaining a predetermined quantity of active agent calculated toproduce the desired therapeutic effect either alone or in combinationwith one or more additional units. For example, such unit dosage formsmay be capsules, tablets, pills, and the like, or unit packages suitablefor parenteral administration.

In some embodiments, the pharmaceutical compositions of the disclosureare suitable for oral administration. Suitable pharmaceuticalcompositions for oral administration may be in the form of capsules,tablets, pills, lozenges, cachets, dragees, powders, granules; or as asolution or a suspension in an aqueous or non-aqueous liquid; or as anoil-in-water or water-in-oil liquid emulsion; or as an elixir or syrup;and the like; each containing a predetermined amount of a compound ofthe present disclosure as an active ingredient.

When intended for oral administration in a solid dosage form (i.e., ascapsules, tablets, pills and the like), the pharmaceutical compositionsof the disclosure will typically comprise the active agent and one ormore pharmaceutically-acceptable carriers. Optionally, such solid dosageforms may comprise: fillers or extenders, such as starches,microcrystalline cellulose, lactose, dicalcium phosphate, sucrose,glucose, mannitol, and/or silicic acid; binders, such ascarboxymethylcellulose, alginates, gelatin, polyvinyl pyrrolidone,sucrose and/or acacia; humectants, such as glycerol; disintegratingagents, such as crosscarmellose sodium, agar-agar, calcium carbonate,potato or tapioca starch, alginic acid, certain silicates, and/or sodiumcarbonate; solution retarding agents, such as paraffin; absorptionaccelerators, such as quaternary ammonium compounds; wetting agents,such as cetyl alcohol and/or glycerol monostearate; absorbents, such askaolin and/or bentonite clay; lubricants, such as talc, calciumstearate, magnesium stearate, solid polyethylene glycols, sodium laurylsulfate, and/or mixtures thereof; coloring agents; and buffering agents.

Release agents, wetting agents, coating agents, sweetening, flavoringand perfuming agents, preservatives and antioxidants can also be presentin the pharmaceutical compositions of the disclosure. Examples ofpharmaceutically-acceptable antioxidants include: water-solubleantioxidants, such as ascorbic acid, cysteine hydrochloride, sodiumbisulfate, sodium metabisulfate, sodium sulfite and the like;oil-soluble antioxidants, such as ascorbyl palmitate, butylatedhydroxyanisole, butylated hydroxytoluene, lecithin, propyl gallate,alpha-tocopherol, and the like; and metal-chelating agents, such ascitric acid, ethylenediamine tetraacetic acid, sorbitol, tartaric acid,phosphoric acid, and the like. Coating agents for tablets, capsules,pills and like, include those used for enteric coatings, such ascellulose acetate phthalate, polyvinyl acetate phthalate, hydroxypropylmethylcellulose phthalate, methacrylic acid, methacrylic acid estercopolymers, cellulose acetate trimellitate, carboxymethyl ethylcellulose, hydroxypropyl methyl cellulose acetate succinate, and thelike.

Pharmaceutical compositions of the disclosure may also be formulated toprovide slow or controlled release of the active agent using, by way ofexample, hydroxypropyl methylcellulose in varying proportions; or otherpolymer matrices, liposomes and/or microspheres. In addition, thepharmaceutical compositions of the disclosure may optionally containopacifying agents and may be formulated so that they release the activeingredient only, or preferentially, in a certain portion of thegastrointestinal tract, optionally, in a delayed manner. Examples ofembedding compositions which can be used include polymeric substancesand waxes. The active agent can also be in micro-encapsulated form, ifappropriate, with one or more of the above-described excipients.

Suitable liquid dosage forms for oral administration include, by way ofillustration, pharmaceutically-acceptable emulsions, microemulsions,solutions, suspensions, syrups and elixirs. Liquid dosage formstypically comprise the active agent and an inert diluent, such as, forexample, water or other solvents, solubilizing agents and emulsifiers,such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethylacetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butyleneglycol, oils (e.g., cottonseed, groundnut, corn, germ, olive, castor andsesame oils), oleic acid, glycerol, tetrahydrofuryl alcohol,polyethylene glycols and fatty acid esters of sorbitan, and mixturesthereof. Alternatively, certain liquid formulations can be converted,for example, by spray drying, to a powder, which is used to preparesolid dosage forms by conventional procedures.

Suspensions, in addition to the active ingredient, may containsuspending agents such as, for example, ethoxylated isostearyl alcohols,polyoxyethylene sorbitol and sorbitan esters, microcrystallinecellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth,and mixtures thereof.

The compounds of this disclosure, or a pharmaceutically acceptable saltthereof, can also be administered parenterally (e.g., by intravenous,subcutaneous, intramuscular or intraperitoneal injection). Forparenteral administration, the active agent is typically admixed with asuitable vehicle for parenteral administration including, by way ofexample, sterile aqueous solutions, saline, low molecular weightalcohols such as propylene glycol, polyethylene glycol, vegetable oils,gelatin, fatty acid esters such as ethyl oleate, and the like.Parenteral formulations may also contain one or more anti-oxidants,solubilizers, stabilizers, preservatives, wetting agents, emulsifiers,buffering agents, or dispersing agents. These formulations may berendered sterile by use of a sterile injectable medium, a sterilizingagent, filtration, irradiation, or heat.

Alternatively, the pharmaceutical compositions of the disclosure areformulated for administration by inhalation. Suitable pharmaceuticalcompositions for administration by inhalation will typically be in theform of an aerosol or a powder. Such compositions are generallyadministered using well-known delivery devices, such as a metered-doseinhaler, a dry powder inhaler, a nebulizer or a similar delivery device.

When administered by inhalation using a pressurized container, thepharmaceutical compositions of the disclosure will typically comprisethe active ingredient and a suitable propellant, such asdichlorodifluoromethane, trichlorofluoromethane,dichlorotetrafluoroethane, carbon dioxide or other suitable gas.Additionally, the pharmaceutical composition may be in the form of acapsule or cartridge (made, for example, from gelatin) comprising acompound of the disclosure and a powder suitable for use in a powderinhaler. Suitable powder bases include, by way of example, lactose orstarch.

The compounds of the disclosure, or a pharmaceutically acceptable saltthereof, may also be formulated for topical administration to the skinas an ointment or cream. Ointment formulations are semisolidpreparations having a base of an oily or greasy material that istypically clear. Suitable oily materials for use in ointmentformulations include petrolatum (petroleum jelly), beeswax, cocoabutter, shea butter, and cetyl alcohol. Ointments may optionallyadditionally include emollients and penetration enhancers, if desired.

Cream formulations may be prepared as emulsions comprising an oil phaseand aqueous phase, typically including purified water. Components ofcream formulations may include: oil bases, such as petrolatrum, mineraloils, vegetable and animal oils, and triglycerides; cream bases, such aslanolin alcohols, stearic acid, and cetostearyl alcohol; a gel base,such as polyvinyl alcohol; solvents, such as, propylene glycol andpolyethylene glycol; emulsifiers, such as polysorbates, stearates, suchas glyceryl stearate, octylhydroxystearate, polyoxyl stearate, PEGstearyl ethers, isopropyl palmitate, and sorbitan monostearate;stabilizers, such as polysaccharides and sodium sulfite; emollients(i.e.moisturizers), such as medium chain triglycerides, isopropylmyristate, and dimethicone; stiffening agents, such as cetyl alcohol andstearyl alcohol; antimicrobial agents, such as methylparaben,propylparaben, phenoxyethanol, sorbic acid, diazolidinyl urea, andbutylated hydroxyanisole; penetration enhancers, such asN-methylpyrrolidone, propylene glycol, polyethylene glycol monolaurate,and the like; and chelating agents, such as edetate disodium.

The following non-limiting examples illustrate representativepharmaceutical compositions of the present invention.

Tablet Oral Solid Dosage Form

A compound of the disclosure or a pharmaceutically-acceptable saltthereof is dry blended with microcrystalline cellulose, polyvinylpyrrolidone, and crosscarmellose sodium in a ratio of 4:5:1:1 andcompressed into tablets to provide a unit dosage of, for example, 5 mg,20 mg or 40 mg active agent per tablet.

Capsule Oral Solid Dosage Form

A compound of the disclosure or a pharmaceutically-acceptable saltthereof is combined with microcrystalline cellulose, polyvinylpyrrolidone, and crosscarmellose sodium in a ratio of 4:5:1:1 by wetgranulation and loaded into gelatin or hydroxypropyl methylcellulosecapsules to provide a unit dosage of, for example, 5 mg, 20 mg or 40 mgactive agent per capsule.

Liquid Formulation

A liquid formulation comprising a compound of the disclosure (0.1%),water (98.9%) and ascorbic acid (1.0%) is formed by adding a compound ofthe disclosure to a mixture of water and ascorbic acid.

Enteric Coated Oral Dosage Form

A compound of the disclosure is dissolved in an aqueous solutioncontaining polyvinyl pyrrolidone and spray coated onto microcrystallinecellulose or sugar beads in a ratio of 1:5 w/w active agent:beads andthen an approximately 5% weight gain of an enteric coating comprising anacrylic copolymer, for example a combination of acrylic copolymersavailable under the trade names Eudragit-L® and Eudragit-S®, orhydroxypropyl methylcellulose acetate succinate is applied. The entericcoated beads are loaded into gelatin or hydroxypropyl methylcellulosecapsules to provide a unit dosage of, for example, 30 mg active agentper capsule.

Enteric Coated Oral Dosage Form

An enteric coating comprising a combination of Eudragit-L® andEudragit-S®, or hydroxypropyl methylcellulose acetate succinate isapplied to a tablet oral dosage form or a capsule oral dosage formdescribed above.

Ointment Formulation for Topical Administration

A compound of the disclosure is combined with petrolatum, C₅-C₁₀triglyceride, octylhydroxystearate, and N-methylpyrrolidone in a ratioto provide a composition containing 0.05% to 5% active agent by weight.

Ointment Formulation for Topical Administration

A compound of the disclosure is combined with white petrolatum,propylene glycol, mono- and di-glycerides, paraffin, butylatedhydroxytoluene, and edetate calcium disodium in a ratio to provide acomposition containing 0.05% to 5% active agent by weight.

Ointment Formulation for Topical Administration

A compound of the disclosure is combined with mineral oil, paraffin,propylene carbonate, white petrolatum and white wax to provide acomposition containing 0.05% to 5% active agent by weight.

Cream Formulation for Topical Administration

Mineral oil is combined with a compound of the disclosure, propyleneglycol, isopropyl palmitate, polysorbate 60, cetyl alcohol, sorbitanmonostearate, polyoxyl 40 stearate, sorbic acid, methylparaben andpropylparaben to form an oil phase, which is combined with purifiedwater by shear blending to provide a composition containing 0.05% to 5%active agent by weight.

Cream Formulation for Topical Administration

A cream formulation comprising a compound of the disclosure, benzylalcohol, cetyl alcohol, citric acid anhydrous, mono and di-glycerides,oleyl alcohol, propylene glycol, sodium cetostearyl sulphate, sodiumhydroxide, stearyl alcohol, triglycerides, and water contains 0.05% to5% active agent by weight.

Cream formulation for topical administration A cream formulationcomprising a compound of the disclosure, cetostearyl alcohol, isopropylmyristate, propylene glycol, cetomacrogol 1000, dimethicone 360, citricacid, sodium citrate, and purified water, with imidurea, methylparaben,and propylparaben, as preservatives, contains 0.05% to 5% active agentby weight.

Utility

Inhibition of JAK3 blocks the signaling of many key pro-inflammatorycytokines. Thus the compounds of the disclosure are expected to beuseful in the treatment of inflammatory diseases.

The compounds of the disclosure have been designed to be selective forJAK3 over JAK1, JAK2 and TYK2. Selectivity for JAK3 over JAK1 isanticipated to be beneficial as there is some evidence that JAK3selectivity allows sparing of potentially beneficial cytokines such asIL-10 which has been involved in mucosal healing, IL-22 which isinvolved in mucus barrier protection and epithelial regeneration, andIL-6 which is involved in the proliferation of intestinal epithelialcells. Selectivity for JAK3 over JAK2 allows sparing of erythropoietin(EPO) and thrombopoietin (TPO) signaling.

Without being limited by this theory, the compounds of the disclosurepossess an electrophilic portion which may form a covalent bond with thecysteine (Cys909) present in JAK3, a residue replaced by a serine in theother three JAK isoforms (Goedken et al., J Biol Chem., 2015, 290, 8,4573-89). Such covalent binding to JAK3 could be beneficial by providingan extended target engagement which may translate in better efficacy.

Additionally, certain compounds of the disclosure have minimal systemicexposure, thereby avoiding potential adverse systemic immunosuppressiveeffects.

Gastrointestinal Inflammatory Disease

In addition to providing potent inhibition of JAK3, some compounds ofthe disclosure have been designed to be poorly absorbed to minimizesystemic exposure. These compounds are designed to have their effect atthe site of action, for example, in the colon. Certain compounds exhibitlow permeabilities with K_(p) values less than about 5×10⁻⁶ cm/sec,which is considered favorable to minimize systemic exposure and targetthe colon. Certain compounds have a K_(p) value less than about 10×10⁻⁶cm/sec which may also be sufficient to minimize systemic exposure andtarget the colon. As described in the experimental section, compounds12, 13, 16, and 24 exhibited a colon to plasma ratio in excess of 200.Compound 15 exhibited a colon to plasma ratio in excess of 30. Compound30 exhibited a colon to plasma ratio in excess of 8.

It is expected that a high colon to plasma ratio will provide robust,luminally-driven anti-inflammatory activity without associated,systemically-driven, adverse effects. The compounds of the disclosureare expected to be useful for a variety of gastrointestinal inflammatoryindications that include, but are not limited to, inflammatory boweldisease, ulcerative colitis (proctosigmoiditis, pancolitis, ulcerativeproctitis and left-sided colitis), Crohn's disease, collagenous colitis,lymphocytic colitis, Behcet's disease, celiac disease, immune checkpointinhibitor induced colitis, ileitis, eosinophilic esophagitis, graftversus host disease-related colitis, and infectious colitis. Ulcerativecolitis (Reimund et al., J Clin Immunology, 1996, 16, 144-150), Crohn'sdisease (Woywodt et al., Eur J Gastroenterology Hepatology, 1999, 11,267-276), collagenous colitis (Kumawat et al., Mol Immunology, 2013, 55,355-364), lymphocytic colitis (Kumawat et al., 2013), eosinophilicesophagitis (Weinbrand-Goichberg et al., Immunol Res, 2013, 56,249-260), graft versus host disease-related colitis (Coghill et al.,Blood, 2001, 117, 3268-3276), infectious colitis (Stallmach et al., IntJ Colorectal Dis, 2004, 19, 308-315), Behcet's disease (Zhou et al.,Autoimmun Rev, 2012, 11, 699-704), celiac disease (de Nitto et al.,World JGastroenterol, 2009, 15, 4609-4614), immune checkpoint inhibitorinduced colitis (e.g., CTLA-4 inhibitor-induced colitis; (Yano et al., JTranslation Med, 2014, 12, 191), PD-1- or PD-L1-inhibitor-inducedcolitis), and ileitis (Yamamoto et al., Dig Liver Dis, 2008, 40,253-259) are characterized by elevation of certain pro-inflammatorycytokine levels. As many pro-inflammatory cytokines signal via JAKactivation, compounds described in this application are expected to beable to alleviate the inflammation and provide symptom relief.

In particular, the compounds of the disclosure are expected to be usefulfor the induction and maintenance of remission of ulcerative colitis,and for the treatment of Crohn's disease, immune checkpoint inhibitorinduced colitis, celiac disease, and the gastrointestinal adverseeffects in graft versus host disease.

In one aspect, therefore, the invention provides a method of treating agastrointestinal inflammatory disease in a mammal (e.g., a human), themethod comprising administering to the mammal a compound of thedisclosure, or a pharmaceutically acceptable salt thereof, or apharmaceutical composition comprising a pharmaceutically-acceptablecarrier and a compound of the disclosure, or a pharmaceuticallyacceptable salt thereof. In some embodiments, the gastrointestinalinflammatory disease is ulcerative colitis. In some embodiments, thegastrointestinal inflammatory disease is celiac disease. In someembodiments, the gastrointestinal inflammatory disease is Crohn'sdisease. In some embodiments, the gastrointestinal inflammatory diseaseis immune checkpoint inhibitor induced colitis. In some embodiments, thegastrointestinal inflammatory disease is gastrointestinal adverseeffects in graft versus host disease.

The invention further provides a method of treating ulcerative colitis,celiac disease, or Crohn's disease in a mammal, the method comprisingadministering to the mammal a compound of the disclosure, or apharmaceutically acceptable salt thereof, or a pharmaceuticalcomposition comprising a pharmaceutically-acceptable carrier and acompound of the disclosure, or a pharmaceutically acceptable saltthereof.

When used to treat ulcerative colitis, celiac disease, or Crohn'sdisease, the compounds of the disclosure, or a pharmaceuticallyacceptable salt thereof will typically be administered orally in asingle daily dose or in multiple doses per day, although other forms ofadministration may be used. The amount of active agent administered perdose or the total amount administered per day will typically bedetermined by a physician, in the light of the relevant circumstances,including the condition to be treated, the chosen route ofadministration, the actual compound administered and its relativeactivity, the age, weight, and response of the individual patient, theseverity of the patient's symptoms, and the like.

Suitable doses for treating ulcerative colitis, celiac disease, Crohn'sdisease and other gastrointestinal inflammatory disorders are expectedto range from about 1 to about 400 mg/day of active agent, includingfrom about 5 to about 300 mg/day and from about 20 to about 70 mg perday of active agent for an average 70 kg human.

Combination Therapy

Compounds of the disclosure, or pharmaceutically acceptable saltsthereof may also be used in combination with one or more agents whichact by the same mechanism or by different mechanisms to effect treatmentof gastrointestinal inflammatory disorders. The different agents may beadministered sequentially or simultaneously (in separate compositions orin the same composition). Useful classes of agents for combinationtherapy include, but are not limited to, aminosalicylates, steroids,systemic immunosuppressants, anti-TNFα antibodies, TNF alpha ligandinhibitor, TNF binding agent, anti-VLA-4 antibodies, anti-integrin 47antibodies, anti-bacterial agents, Glucocorticoid agonists, Nuclearfactor kappa B inhibitors, 5-Lipoxygenase inhibitors, integrinalpha-4/beta-7 antagonist, Cyclooxygenase inhibitors, IL-23 antagonists,Leukotriene BLT receptor antagonist, IL-6 antagonists, IL-8 antagonists,integrin antagonists, nicotinic acetylcholine receptor agonists, PPARgamma agonists, sphingosine-1-phosphate receptor-1 modulators,B-lymphocyte antigen CD20 inhibitors, calcineurin inhibitors, CD3antagonist, cell adhesion molecule inhibitors, eosinophil peroxidaseinhibitors, heparin agonists, ICAM1 gene inhibitors, IL-13 antagonists,IL-2 receptor alpha subunit inhibitors, insulin sensitizers, interferonbeta ligands, interferon gamma receptor antagonists, interleukin-1 betaligand modulators, MAdCAM inhibitors, PDE 4 inhibitors,sphingosine-1-phosphate receptor-1 agonists, TLR-9 agonists,acetylcholinesterase inhibitors, ACTH receptor agonists, activinreceptor antagonists, CCR5 chemokine antagonists, CCR9 chemokineantagonists, and anti-diarrheal medicines.

Aminosalicylates that may be used in combination with the present JAKinhibitor compounds include, but are not limited to, mesalamine,osalazine and sulfasalazine. Examples of steroids include, but are notlimited to, prednisone, prednisolone, hydrocortisone, budesonide,beclomethasone, and fluticasone. Systemic immunosuppressants useful fortreatment of inflammatory disorders include, but are not limited tocyclosporine, azathioprine, methotrexate, 6-mercaptopurine, andtacrolimus. Further, anti-TNFα antibodies, which include, but are notlimited to, infliximab, adalimumab, golimumab, and certolizumab, may beused in combination therapy. Useful compounds acting by other mechanismsinclude anti-VLA-4 antibodies, such as natalizumab, anti-integrin α₄β₇antibodies, such as vedolizumab, anti-bacterial agents, such asrifaximin, and anti-diarrheal medicines, such as loperamide. (Mozaffariet al. Expert Opin. Biol. Ther. 2014, 14, 583-600; Danese, Gut, 2012,61, 918-932; Lam et al., Immunotherapy, 2014, 6, 963-971.)

Other compounds that may be used in combination with the present JAKinhibitor compounds include, but are not limited to opaganib, abatacept,mongersen, filgotinib, LYC-30937, BI-655130, mirikizumab, adalimumab,tacrolimus, rituximab, GSK-2982772, andecaliximab, naltrexone,risankizumab, QBECO, alicaforsen, etrolizumab, foralumab, ocrelizumab,vedolizumab, amiselimod, ozanimod, dolcanatide, catridecacog,budesonide, STNM-01, cannabidiol, telotristat etiprate, SHP-647,carotegrast methyl, peg-ilodecakin, TOP-1288, iberogast N, PF-06480605,peficitinib, beclomethasone, recombinant interferon beta-1a, infliximab,golimumab, tralokinumab, ustekinumab, certolizumab pegol, thalidomide,upadacitinib, apremilast, natalizumab, interferon beta-1a, rifaximin,RBX-2660, etrasimod, zileuton, fingolimod, cobitolimod, ropivacaine,ABX-464, PF-06700841, prednisolone, GLPG-0974, valganciclovir,ciclosporin, VB-201, tulinercept, MDGN-002, PTG-100, dexamethasone,GED-0507-34-Levo, bertilimumab, brazikumab, KHK-4083, rosiglitazone,mocravimod, sotrastaurin, KAG-308, PUR-0110, E-6007, balsalazide,basiliximab, LP-02, ASP-3291, Trichuris suis ova, K(D)PT, midismase,DNVX-078, vatelizumab, alequel, low molecular weight heparin,metenkefalin, tridecactide, HMPL-004, SB-012, olsalazine, balsalazide,propionyl-L-camitine, Clostridium butyricum, beclomethasone andacemannan.

In another aspect, therefore, the invention provides a therapeuticcombination for use in the treatment of gastrointestinal inflammatorydisorders, the combination comprising a compound of the disclosure, or apharmaceutically acceptable salt thereof, and one or more othertherapeutic agents useful for treating gastrointestinal inflammatorydisorders, such as the ones illustrated above. For example, theinvention provides a combination comprising a compound of thedisclosure, or a pharmaceutically acceptable salt thereof, and one ormore agents selected from aminosalicylates, steroids, systemicimmunosuppressants, anti-TNFα antibodies, anti-VLA-4 antibodies,anti-integrin 407 antibodies, anti-bacterial agents, and anti-diarrhealmedicines. Secondary agent(s), when included, are present in atherapeutically effective amount, i.e. in any amount that produces atherapeutically beneficial effect when co-administered with a compoundof the disclosure or a pharmaceutically acceptable salt thereof.

Also provided, therefore, is a pharmaceutical composition comprising acompound of the disclosure, or a pharmaceutically acceptable saltthereof, and one or more other therapeutic agents useful for treatinggastrointestinal inflammatory disorders.

Further, in a method aspect, the invention provides a method of treatinggastrointestinal inflammatory disorders, the method comprisingadministering to the mammal a compound of the disclosure, or apharmaceutically acceptable salt thereof, and one or more othertherapeutic agents useful for treating gastrointestinal inflammatorydisorders.

When used in combination therapy, the agents may be formulated in asingle pharmaceutical composition, as disclosed above, or the agents maybe provided in separate compositions that are administeredsimultaneously or at separate times, by the same or by different routesof administration. When administered separately, the agents areadministered sufficiently close in time so as to provide a desiredtherapeutic effect.

Such compositions can be packaged separately or may be packaged togetheras a kit. The two or more therapeutic agents in the kit may beadministered by the same route of administration or by different routesof administration.

Inflammatory Skin Disease

Atopic dermatitis and other inflammatory skin diseases have beenassociated with elevation of proinflammatory cytokines that rely on theJAK-STAT pathway. Therefore, the compounds of the disclosure, or apharmaceutically acceptable salt thereof, or a crystalline form thereof,may be beneficial in a number of dermal inflammatory or pruriticconditions that include, but are not limited to atopic dermatitis,alopecia areata, vitiligo, psoriasis, dermatomyositis, cutaneous T celllymphoma (Netchiporouk et al., Cell Cycle. 2014; 13, 3331-3335) andsubtypes (Sezary syndrome, mycosis fungoides, pagetoid reticulosis,granulomatous slack skin, lymphomatoid papulosis, pityriasis lichenoideschronica, pityriasis lichenoides et varioliformis acuta, CD30+ cutaneousT-cell lymphoma, secondary cutaneous CD30+ large cell lymphoma,non-mycosis fungoides CD30− cutaneous large T-cell lymphoma, pleomorphicT-cell lymphoma, Lennert lymphoma, subcutaneous T-cell lymphoma,angiocentric lymphoma, blastic NK-cell lymphoma), prurigo nodularis,lichen planus, primary localized cutaneous amyloidosis, bullouspemphigoid, skin manifestations of graft versus host disease,pemphigoid, discoid lupus, granuloma annulare, lichen simplex chronicus,vulvar/scrotal/perianal pruritus, lichen sclerosus, post herpeticneuralgia itch, lichen planopilaris, and foliculitis decalvans. Inparticular, atopic dermatitis (Bao et al., JAK-STAT, 2013, 2, e24137),alopecia areata (Xing et al., Nat Med. 2014, 20, 1043-1049), vitiligo(Craiglow et al, JAMA Dermatol. 2015, 151, 1110-1112), prurigo nodularis(Sonkoly et al., J Allergy Clin Immunol. 2006, 117, 411-417), lichenplanus (Welz-Kubiak et al., J Immunol Res. 2015, ID:854747), primarylocalized cutaneous amyloidosis (Tanaka et al., Br J Dermatol. 2009,161, 1217-1224), bullous pemphigoid (Feliciani et al., Int JImmunopathol Pharmacol. 1999, 12, 55-61), and dermal manifestations ofgraft versus host disease (Okiyama et al., J Invest Dermatol. 2014, 134,992-1000) are characterized by elevation of certain cytokines thatsignal via JAK activation. Accordingly, compounds of the disclosure, ora pharmaceutically acceptable salt thereof, have the potential toalleviate associated dermal inflammation or pruritus driven by thesecytokines. In particular, compounds of the disclosure, or apharmaceutically acceptable salt thereof, are expected to be useful forthe treatment of atopic dermatitis and other inflammatory skin diseases.

In one aspect, therefore, the invention provides a method of treating aninflammatory skin disease in a mammal (e.g., a human), the methodcomprising applying a pharmaceutical composition comprising a compoundof the disclosure, or a pharmaceutically acceptable salt thereof, and apharmaceutical carrier to the skin of the mammal. In one aspect, theinflammatory skin disease is atopic dermatitis.

Compounds of the disclosure, or a pharmaceutically acceptable saltthereof, may also be used in combination with one or more compounduseful to treat inflammatory skin diseases. In some embodiments, the oneor more compound is a steroid, Histamine H1 receptor antagonist,calcineurin inhibitor, IL-13 antagonist, PDE 4 inhibitor, G-proteincoupled receptor-44 antagonist, IL-4 antagonist, 5-HT 1a receptorantagonist, 5-HT 2b receptor antagonist, Alpha 2 adrenoceptor agonist,cannabinoid CB1 receptor antagonist, CCR3 chemokine, antagonist,collagenase inhibitor, cytosolic phospholipase A2 inhibitor, eotaxinligand inhibitor, GATA 3 transcription factor inhibitor, Histamine H4receptor antagonist, IL-10 antagonist, IL-12 antagonist, IL-17antagonist, IL-2 antagonist, IL-23 antagonist, IL-4 receptor modulator,IL-5 antagonist, immunoglobulin E antagonist, immunoglobulin Emodulator, interferon gamma receptor antagonist, Interleukin 33 ligandinhibitor, Interleukin-31 receptor antagonist, Leukotriene antagonist,Liver X receptor agonist, Liver X receptor beta agonist, nuclear factorkappa B inhibitor, OX-40 receptor antagonist, PGD2 antagonist,phospholipase A2 inhibitor, SH2 domain inositol phosphatase 1stimulator, thymic stromal lymphoprotein ligand inhibitor, TLRmodulator, TNF alpha ligand modulator, or vanilloid VR1 antagonist. Insome embodiments, the one or more compound is a gram positiveantibiotic, such as mupirocin or fusidic acid. In some embodiments, theone or more compound is tranilast, tacrolimus, epinastine, SB-011,AM-1030, ZPL-521, MM-36, FB-825, PG-102, viromed, GBR-830, AVX-001,AMG-0101, E-6005, DMT-210, AX-1602, bertilimumab, rosiptor acetate,Q-301, ANB-020, VTP-38543, ZPL-389, lebrikizumab, tezepelumab,fexofenadine, pimecrolimus, bepotastine, crisaborole, tralokinumab,fevipiprant, doxycycline, desloratadine, ALX-101, nemolizumab,asivatrep, ciclosporin, mepolizumab, dupilumab, secukinumab,timapiprant, or ustekinumab.

In one aspect, therefore, the invention provides a method of treating aninflammatory skin disease in a mammal, the method comprising applying acompound of the disclosure, or a pharmaceutically acceptable saltthereof, and a gram positive antibiotic to the skin of the mammal. Inanother aspect, the invention provides a pharmaceutical compositioncomprising a compound of the disclosure, or a pharmaceuticallyacceptable salt thereof, a gram positive antibiotic, and apharmaceutically-acceptable carrier.

Respiratory Diseases

Cytokines which signal through the JAK-STAT pathway, in particular IL-2,IL-3, IL-4, IL-5, IL-6, IL-9, IL-11, IL-13, IL-23, IL-31, IL-27, thymicstromal lymphopoietin (TSLP), interferon-γ (IFNγ) andgranulocyte-macrophage colony-stimulating factor (GM-CSF) have also beenimplicated in asthma inflammation and in other inflammatory respiratorydiseases. As described above, the compounds of the disclosure have beenshown to be potent inhibitors of JAK3 and have also demonstrated potentinhibition of IL-2 pro-inflammatory cytokines in cellular assays.

The anti-inflammatory activity of JAK inhibitors has been robustlydemonstrated in preclinical models of asthma (Malaviya et al., IntImmunopharmacol, 2010, 10, 829,-836; Matsunaga et al., Biochem andBiophys Res Commun, 2011, 404, 261-267; Kudlacz et al., Eur J Pharmacol,2008, 582, 154-161.) Accordingly, the compounds of the disclosure, or apharmaceutically acceptable salt thereof, are expected to be useful forthe treatment of inflammatory respiratory disorders such as asthma.Inflammation and fibrosis of the lung is characteristic of otherrespiratory diseases in addition to asthma such as chronic obstructivepulmonary disease (COPD), cystic fibrosis (CF), pneumonitis,interstitial lung diseases (including idiopathic pulmonary fibrosis),acute lung injury, acute respiratory distress syndrome, bronchitis,emphysema, and bronchiolitis obliterans. The compounds of thedisclosure, or a pharmaceutically acceptable salt thereof, therefore,may be useful for the treatment of chronic obstructive pulmonarydisease, cystic fibrosis, pneumonitis, interstitial lung diseases(including idiopathic pulmonary fibrosis), acute lung injury, acuterespiratory distress syndrome, bronchitis, emphysema, bronchiolitisobliterans, bronchiolitis obliterans organizing pneumonia (also termedCOS), primary Graft Dysfunction (PGD), organizing pneumonia (OP), acuterejection (AR), lymphocytic bronchiolitis (LB), chronic Lung AllograftDysfunction (CLAD), restrictive CLAD (rCLAD or RAS), neutrophilicallograft dysfunction, and sarcoidosis.

In one aspect, therefore, the disclosure provides a method of treating arespiratory disease in a mammal (e.g., a human), the method comprisingadministering to the mammal a compound of the disclosure, or apharmaceutically-acceptable salt thereof.

In one aspect, the respiratory disease is asthma, chronic obstructivepulmonary disease, cystic fibrosis, pneumonitis, chronic obstructivepulmonary disease (COPD), cystic fibrosis (CF), pneumonitis,interstitial lung diseases (including idiopathic pulmonary fibrosis),acute lung injury, acute respiratory distress syndrome, bronchitis,emphysema, bronchiolitis obliterans, bronchiolitis obliterans organizingpneumonia (also termed COS), primary Graft Dysfunction (PGD), organizingpneumonia (OP), acute rejection (AR), lymphocytic bronchiolitis (LB),chronic Lung Allograft Dysfunction (CLAD), restrictive CLAD (rCLAD orRAS), neutrophilic allograft dysfunction, allergic rhinitis orsarcoidosis. In another aspect, the respiratory disease is asthma orchronic obstructive pulmonary disease.

In a further aspect, the respiratory disease is a lung infection, ahelminthic infection, pulmonary arterial hypertension, sarcoidosis,lymphangioleiomyomatosis, bronchiectasis, or an infiltrative pulmonarydisease. In yet another aspect, the respiratory disease is drug-inducedpneumonitis, fungal induced pneumonitis, allergic bronchopulmonaryaspergillosis, hypersensitivity pneumonitis, eosinophilic granulomatosiswith polyangiitis, idiopathic acute eosinophilic pneumonia, idiopathicchronic eosinophilic pneumonia, hypereosinophilic syndrome, Lofflersyndrome, bronchiolitis obliterans organizing pneumonia, orimmune-checkpoint-inhibitor induced pneumonitis.

The disclosure further provides a method of treating a respiratorydisease, the method comprising administering to the mammal apharmaceutical composition comprising a compound of the disclosure, or apharmaceutically-acceptable salt thereof, and apharmaceutically-acceptable carrier.

Compounds of the disclosure, or pharmaceutically acceptable saltsthereof, may also be used in combination with one or more compounduseful to respiratory diseases.

Ocular Diseases

Many ocular diseases have been shown to be associated with elevations ofproinflammatory cytokines that rely on the JAK-STAT pathway.

The compounds of the disclosure, or a pharmaceutically acceptable saltthereof, therefore, may be useful for the treatment of a number ofocular diseases that include, but are not limited to, uveitis, diabeticretinopathy, diabetic macular edema, dry eye disease, age-relatedmacular degeneration, retinal vein occlusion (RVO) and atopickeratoconjunctivitis.

In particular, uveitis (Horai and Caspi, J Interferon Cytokine Res,2011, 31, 733-744), diabetic retinopathy (Abcouwer, J Clin Cell Immunol,2013, Suppl 1, 1-12), diabetic macular edema (Sohn et al., AmericanJournal of Opthamology, 2011, 152, 686-694), dry eye disease (Stevensonet al, Arch Ophthalmol, 2012, 130, 90-100), retinal vein occlusion(Shchuko et al, Indian Journal of Ophthalmology, 2015, 63(12), 905-911)and age-related macular degeneration (Knickelbein et al, Int OphthalmolClin, 2015, 55(3), 63-78) are characterized by elevation of certainpro-inflammatory cytokines that signal via the JAK-STAT pathway.Accordingly, compounds of the disclosure, or a pharmaceuticallyacceptable salt thereof, may be able to alleviate the associated ocularinflammation and reverse disease progression or provide symptom relief.

In one aspect, therefore, the disclosure provides a method of treatingan ocular disease in a mammal, the method comprising administering apharmaceutical composition comprising a compound of the disclosure, or apharmaceutically-acceptable salt thereof, and a pharmaceutical carrierto the eye of the mammal. In one aspect, the ocular disease is uveitis,diabetic retinopathy, diabetic macular edema, dry eye disease,age-related macular degeneration, retinal vein occlusion or atopickeratoconjunctivitis. In one aspect, the method comprises administeringthe compound of the disclosure, or a pharmaceutically acceptable saltthereof, by intravitreal injection.

Compounds of the disclosure, or a pharmaceutically acceptable saltthereof, may also be used in combination with one or more compounduseful to ocular diseases.

Other Diseases

The compounds of the disclosure, or a pharmaceutically acceptable saltthereof, may also be useful to treat other diseases such as otherinflammatory diseases, autoimmune diseases or cancers.

The compounds of the disclosure, or a pharmaceutically acceptable saltthereof, may be useful to treat one or more of arthritis, rheumatoidarthritis, juvenile rheumatoid arthritis, transplant rejection,xerophthalmia, psoriatic arthritis, diabetes, insulin dependentdiabetes, motor neurone disease, myelodysplastic syndrome, pain,sarcopenia, cachexia, septic shock, systemic lupus erythematosus,leukemia, chronic lymphocytic leukemia, chronic myelocytic leukemia,acute lymphoblastic leukemia, acute myelogenous leukemia, ankylosingspondylitis, myelofibrosis, B-cell lymphoma, hepatocellular carcinoma,Hodgkins disease, breast cancer, Multiple myeloma, melanoma, non-Hodgkinlymphoma, non-small-cell lung cancer, ovarian clear cell carcinoma,ovary tumor, pancreas tumor, polycythemia vera, Sjoegrens syndrome, softtissue sarcoma, sarcoma, splenomegaly, T-cell lymphoma, and thalassemiamajor.

Compounds of the disclosure have been demonstrated to be potentinhibitors of the JAK3 enzyme and to be selective for JAK3 over JAK1,JAK2 and TYK2 in enzyme binding assays and to have potent functionalactivity for JAK3 in a cellular assay as described in the followingexamples.

EXAMPLES

The following synthetic and biological examples are offered toillustrate the invention, and are not to be construed in any way aslimiting the scope of the invention. In the examples below, thefollowing abbreviations have the following meanings unless otherwiseindicated. Abbreviations not defined below have their generally acceptedmeanings.

-   -   ACN=acetonitrile    -   Calcd=calculated    -   Boc=tert-Butyloxycarbonyl    -   d=day(s)    -   DIPEA=N,N-diisopropylethylamine    -   DMF=N,N-dimethylformamide    -   DMSO=dimethyl sulfoxide    -   EtOAc=ethyl acetate    -   EtOH=ethyl alcohol    -   h=hour(s)    -   HATU=N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)uronium        hexafluorophosphate    -   IPA=isopropyl alcohol    -   MeOH=methanol    -   min=minute(s)    -   RT or rt=room temperature    -   SiG=Silica gel    -   TEA=triethylamine    -   THF=tetrahydrofuran    -   THP=tetrahydropyran    -   TFA=trifluoroacetic acid

Reagents and solvents were purchased from commercial suppliers (Aldrich,Fluka, Sigma, etc.), and used without further purification. Progress ofreaction mixtures was monitored by thin layer chromatography (TLC),analytical high performance liquid chromatography (anal. HPLC), and massspectrometry. Reaction mixtures were worked up as described specificallyin each reaction; commonly they were purified by extraction and otherpurification methods such as temperature-, and solvent-dependentcrystallization, and precipitation. In addition, reaction mixtures wereroutinely purified by column chromatography or by preparative HPLC,typically using C18 or BDS column packings and conventional eluents.Typical preparative HPLC conditions are described below.

Characterization of reaction products was routinely carried out by massand ¹H-NMR spectrometry. For NMR analysis, samples were dissolved indeuterated solvent (such as CD₃OD, CDCl₃, or d₆-DMSO), and ¹H-NMRspectra were acquired with a Varian Gemini 2000 instrument (400 MHz)under standard observation conditions. Mass spectrometric identificationof compounds was performed by an electrospray ionization method (ESMS)with an Applied Biosystems (Foster City, Calif.) model API 150 EXinstrument or a Waters (Milford, Mass.) 3100 instrument, coupled toautopurification systems.

Unless otherwise indicated the following conditions were used forpreparative HPLC purifications.

-   Column: C18, 5 μm 21.2×150 mm or C18, 5 μm 21×250 mm or C14, 5 μm    21×150 mm-   Column temperature: Room Temperature-   Flow rate: 20.0 mL/min-   Mobile Phases: A=Water+0.05% TFA    -   B=ACN+0.05% TFA,-   Injection volume: (100-1500 μL)-   Detector wavelength: 214 nm

Crude compounds were dissolved in 1:1 water:acetic acid at about 50mg/mL. A 4 minute analytical scale test run was carried out using a2.1×50 mm C18 column followed by a 15 or 20 minute preparative scale runusing 100 μL injection with the gradient based on the % B retention ofthe analytical scale test run. Exact gradients were sample dependent.Samples with close running impurities were checked with a 21×250 mm C18column and/or a 21×150 mm C14 column for best separation. Fractionscontaining desired product were identified by mass spectrometricanalysis.

Analytic HPLC Conditions Method A

-   Column: LUNA C18 (2), 150×4.60 mm, 3 μm-   Column temperature: 37° C.-   Flow rate: 1.0 mL/min-   Injection volume: 5 μL-   Sample preparation: Dissolve in 1:1 ACN:water-   Mobile Phases: A=Water:ACN:TFA (98:2:0.05)    -   B=Water:ACN:TFA (2:98:0.05)-   Detector wavelength: 250 nm-   Gradient: 32 min total (time (min)/% B): 0/2, 10/20, 24/90, 29/90,    30/2, 32/2

Method B

-   Column: LUNA C18 (2), 150×4.60 mm, 3 μm-   Column temperature: 37° C.-   Flow rate: 1.0 mL/min-   Injection volume: 10 μL-   Sample preparation: Dissolve in 1:1 ACN:water-   Mobile Phases: A=Water:ACN:TFA (98:2:0.05)    -   B=Water:ACN:TFA (10:90:0.05)-   Detector wavelength: 254 nm-   Gradient: 35 min total (time (min)/% B): 0/2, 20/25, 23/90, 26/90,    27/2, 35/2

Preparation 1: tert-butyl(S)-3-((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)pyrrolidine-1-carboxylate

To a stirring solution of 6-bromo-8-fluoroimidazo[1,5-a]pyridine (500mg, 2.32 mmol) in DMSO (10 mL) was added tert-butyl(S)-3-hydroxypyrrolidine-1-carboxylate (521 mg, 2.79 mmol) and Cs₂CO₃(1.51 g, 4.65 mmol) at room temperature. The reaction mixture wasallowed to stir at 120° C. for 4 h. The reaction was diluted with waterand extracted with EtOAc. The organic layer was washed with brine, driedover anhydrous Na₂SO₄, filtered, and concentrated under reducedpressure. The crude material was purified by silica gel columnchromatography using a 30-35% EtOAc:hexanes gradient and afforded thedesired product (550 mg, 1.44 mmol). (m/z): [M+H]⁺ calculated forC₁₆H₂₀BrN₃O₃ 383.0 found 383.0.

Preparation 2: tert-butyl(S)-3-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)pyrrolidine-1-carboxylate

To a stirring solution of tert-butyl(S)-3-((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)pyrrolidine-1-carboxylate(550 mg, 1.43 mmol) in dioxane (12 mL) and water (3 mL) was added(4-hydroxyphenyl)boronic acid (238 mg, 1.72 mmol) and Na₂CO₃ (305 mg,2.86 mmol). The reaction was purged with argon for 15 mn and thenPd(dppf)Cl₂.DCM (117 mg, 0.144 mmol) was added and the reaction wassealed, heated to 120° C., and stirred for 2 h. The reaction was thencooled to room temperature and the organic layer was dried over Na₂SO₄(238 mg, 1.73 mmol) and Na₂CO₃ (305 mg, 2.88 mmol). The mixture was thenfiltered through a celite pad and the filtrate was concentrated underreduced pressure to obtain the crude material. Purification of the crudematerial by silica gel column chromatography using a 30-35%EtOAc:hexanes gradient afforded the desired product (453 mg, 1.15 mmol).(m/z): [M+H]⁺ calculated for C₂₂H₂₅N₃O₄ 396.19 found 396.29.

Preparation 3:(S)-4-(8-(pyrrolidin-3-yloxy)imidazo[1,5-a]pyridin-6-yl)phenol

To a stirring solution of tert-butyl(S)-3-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)pyrrolidine-1-carboxylate(420 mg, 1.088 mmol) in dioxane (15 mL) was added 4M HCl in dioxane (15mL) at 0° C. under a nitrogen atmosphere. The reaction mixture wasstirred for 2 h at room temperature. The reaction was then concentratedunder reduced pressure and dried under high-vacuum to obtain the crudematerial. The crude was triturated with diethyl ether to obtain theproduct as an HCl salt (350 mg, 1.06 mmol). (m/z): [M+H]⁺ calculated forC₁₇H₁₇N₃O₂ 296.14 found 296.11.

Example 1:(S)-1-(3-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)pyrrolidin-1-yl)prop-2-en-1-one

To a stirring solution of(S)-4-(8-(pyrrolidin-3-yloxy)imidazo[1,5-a]pyridin-6-yl)phenol (32 mg,0.095 mmol) in DMF (475 μL) was added DIPEA (83 μL, 0.48 mmol) and thereaction was cooled to 0° C. After 5 minutes of stirring, acryloylchloride (7.7 μL, 0.095 mmol) was added and the reaction was stirred at0° C. for 10 minutes. LCMS analysis indicated formation of the desiredproduct and the reaction was then concentrated in vacuo. The cruderesidue was dissolved in ˜1:1 AcOH:H₂O and purified by reverse phaseHPLC using a 5-45% MeCN:H₂O (with 0.1% TFA) gradient on a Phenomenex21.2×250 mm Luna Axia C18 column to yield the desired product as a TFAsalt (3.2 mg, 0.007 mmol). (m/z): [M+H]⁺ calculated for C₂₀H₁₉N₃O₃ 350.1found 350.1.

Preparation 4: tert-butyl4-(((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)methyl)piperidine-1-carboxylate

To a stirring solution of tert-butyl4-(hydroxymethyl)piperidine-1-carboxylate (451 mg, 2.093 mmol) in DMF(3.5 mL) at 0° C. was added sodium hydride (60% dispersion in mineraloil) (89 mg, 2.2 mmol). The reaction was warmed to room temperature andstirred for 30 minutes. 6-bromo-8-fluoroimidazo[1,5-a]pyridine (300 mg,1.40 mmol) in DMF (3.5 mL) was added to the reaction at 0° C. Thereaction was stirred overnight at room temperature and then quenchedwith 10 mL H₂O and extracted with 3×10 mL EtOAc. The organic extractswere combined and washed with ˜50 mL 1:1 H₂O:brine, dried over Na₂SO₄,filtered, and concentrated onto celite. The crude material was purifiedby silica gel column chromatography using a 0-80% EtOAc:Hex gradient toyield the desired product (290 mg, 1.40 mmol). (m/z): [M+H]⁺ calculatedfor C₁₈H₂₄BrN₃O₃ 411.1 found 411.0.

Preparation 5: tert-butyl4-(((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)piperidine-1-carboxylate

To a stirring solution of tert-butyl4-(((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)methyl)piperidine-1-carboxylate(290 mg, 0.707 mmol) in dioxane (2.8 mL) was added4-hydroxyphenylboronic acid (136 mg, 0.989 mmol), and a solution ofcesium carbonate (691 mg, 2.12 mmol) in water (0.7 mL). The reaction wassealed, heated to 110° C. and stirred overnight. The reaction was cooledto room temperature, concentrated onto celite, and purified by silicagel column chromatography using a 10-80% EtOAc:Hex gradient to affordthe desired product (45 mg, 0.106 mmol). (m/z): [M+H]⁺ calculated forC₂₄H₂₉N₃O₄ 424.2 found 424.1.

Preparation 9:4-(8-(piperidin-4-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)phenol

To a solution of tert-butyl4-(((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)piperidine-1-carboxylatein DCM (500 μL) was added TFA (500 μL) and the reaction was stirred for2 hours before being concentrated in vacuo to afford the crude product(47 mg, 0.106 mmol). (m/z): [M+H]⁺ calculated for C₁₉H₂₁N₃O₂ 324.2 found324.

Example 2:1-(4-(((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)piperidin-1-yl)prop-2-en-1-one

To a stirring solution of4-(8-(piperidin-4-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)phenol in DMF(274 μl) was added DIPEA (57.5 μl, 0.329 mmol) and then acryloylchloride (4.01 μl, 0.049 mmol). The reaction was stirred at roomtemperature for 5 minutes and then concentrated in vacuo. The crudematerial was redissolved in ˜1:1 AcOH:H₂O and purified by reverse phaseHPLC using a 19-50% MeCN:H₂O (0.1% TFA) gradient on a Phenomenex21.2×250 mm Luna Axia C18 column to afford the desired product as a TFAsalt (8.6 mg, 0.017 mmol). (m/z): [M+H]⁺ calculated for C₂₂H₂₂N₃O₃ 378.2found 378.1.

Preparation 9: 4-(8-fluoroimidazo[1,5-a]pyridin-6-yl)phenol

To a stirring solution of 6-bromo-8-fluoroimidazo[1,5-a]pyridine (900mg, 4.19 mmol) in dioxane (13.4 mL) was added 4-hydroxyphenylboronicacid (866 mg, 6.28 mmol), a solution of cesium carbonate (4091 mg, 12.56mmol) in H₂O (3.35 mL), anddichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium (513 mg, 0.628mmol). The reaction was sealed, heated to 110° C. and stirred overnight.The reaction was concentrated directly onto celite and purified bysilica gel column chromatography using a 0-95% EtOAc:Hex gradient toafford the desired product (812 mg, 3.56 mmol). (m/z): [M+H]⁺ calculatedfor C₁₃H₉FN₂O 229.1 found 229.

Preparation 8: tert-butyl5-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)-2-azaspiro[3.3]heptane-2-carboxylate

To a solution of tert-butyl5-hydroxy-2-azaspiro[3.3]heptane-2-carboxylate in DMF (3.3 mL) at 0° C.was added potassium hexamethyldisilazide (1.0 M in THF) (1.78 mL, 1.775mmol) and the reaction was warmed to room temperature and stirred for 20minutes. A solution of 4-(8-fluoroimidazo[1,5-a]pyridin-6-yl)phenol (150mg, 0.657 mmol) in DMF (3.3 mL) was then added to the potassium alkoxidesolution. The resulting reaction was stirred at room temperature for 3hours, then diluted with 10 mL H₂O and extracted with 3×5 mL EtOAc. Theorganic fractions were combined and dried over Na₂SO₄, filtered, andconcentrated onto celite. Purification by silica gel columnchromatography using a 10-100% EtOAc:Hex gradient yielded the desiredproduct (166 mg, 0.394 mmol). (m/z): [M+H]⁺ calculated for C₃₇H₃₆FN₅O₅422.2 found 422.

Preparation 9:4-(8-((2-azaspiro[3.3]heptan-5-yl)oxy)imidazo[1,5-a]pyridin-6-yl)phenol

To a stirring solution of tert-butyl5-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)-2-azaspiro[3.3]heptane-2-carboxylate(166 mg, 0.394 mmol) in DCM (500 μL) was added TFA (500 μL). Thereaction was stirred for 2 hours and then concentrated in vacuo toafford the crude product as a TFA salt. The crude product was usedwithout any further purification and 100% yield was assumed (127 mg,0.394 mmol). (m/z): [M+H]⁺ calculated for C₁₉H₁₉N₃O₂ 322.2 found 322.

Example 3:1-(5-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)-2-azaspiro[3.3]heptan-2-yl)prop-2-en-1-one

To a solution of4-(8-((2-azaspiro[3.3]heptan-5-yl)oxy)imidazo[1,5-a]pyridin-6-yl)phenol(127 mg, 0.395 mmol) in DMF (1.98 mL) was added DIPEA (414 μL, 2.37mmol) and then acryloyl chloride (24.1 μL, 0.296 mmol). The reaction wasstirred for 5 minutes and was then concentrated in vacuo. The cruderesidue was dissolved in ˜1:1 AcOH:H₂O and purified by reverse phaseHPLC using a 15-50% MeCN:H₂O (with 0.1% TFA) gradient on a Phenomenex21.2×250 mm Luna Axia C18 column to afford the desired product (8.6 mg,0.023 mmol). (m/z): [M+H]⁺ calculated for C₁₉H₉N₃O₂ 376.2 found 376.2.

Preparation 10: tert-butyl4-((6-bromoimidazo[1,5-a]pyridin-8-yl)amino)piperidine-1-carboxylate

To a stirring solution of 6-bromo-8-fluoroimidazo[1,5-a]pyridine (560mg, 2.80 mmol) in DMSO (10 ml) was added DIPEA (0.73 mL, 4.20 mmol).Tert-butyl 4-aminopiperidine-1-carboxylate (500 mg, 1.40 mmol) was addedand the reaction was heated to 140° C. and stirred for 16 h. Thereaction was then cooled and diluted with water and extracted EtOAc. Theorganic fraction was washed with brine, dried over Na₂SO₄, filtered, andthen concentrated under reduced pressure to obtain the crude product.Purification of the crude material by silica gel column chromatographyusing a 10% MeOH:DCM solvent system afforded the desired product (160mg, 0.40 mmol). (m/z): [M+H]⁺ calculated for C₁₇H₂₃BrN₄O₂ 396.1 found396.0.

Preparation 11: tert-butyl4-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)amino)piperidine-1-carboxylate

To a pressure tube was added tert-butyl4-((6-bromoimidazo[1,5-a]pyridin-8-yl)amino)piperidine-1-carboxylate(160 mg, 0.406 mmol) in dioxane (12 ml) and H₂O (3 ml) followed by(4-hydroxyphenyl)boronic acid (71 mg, 0.487 mmol) and Na₂CO₃ (91 mg,0.812 mmol). The reaction mixture was purged with argon for 10 minutesand then PdCl₂(dppf) (35 mg, 0.041 mmol) was added. The reaction washeated to 120° C. and stirred for 4 h. The reaction was cooled anddiluted with water and extracted with ethyl acetate, and the organicphase was then washed with water and brine solution. The oganic layerwas dried over Na₂SO₄, filtered, and then concentrated under reducedpressure to obtain the crude product. The crude product was purified bysilica gel column chromatography with 100% EtOAc to afford the desiredproduct.

Preparation 12:4-(8-(piperidin-4-ylamino)imidazo[1,5-a]pyridin-6-yl)phenol

To a stirring solution of tert-butyl4-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)amino)piperidine-1-carboxylate(100 mg, 0.245 mmol) in DCM (10 mL) was added TFA (1 mL) at 0° C. Theresulting reaction mixture was warmed to room temperature at stirred for1 h. The reaction was then concentrated under reduced pressure to obtainthe crude product. The crude product was triturated with diethyl etherto obtain the desired product as a beige solid. (m/z): [M+H]⁺ calculatedfor C₁₈H₂₀N₄O 309.1 found 309.1.

Example 4:1-(4-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)amino)piperidin-1-yl)prop-2-en-1-one

To a stirring solution of4-(8-(piperidin-4-ylamino)imidazo[1,5-a]pyridin-6-yl)phenol (30 mg,0.071 mmol) in DMF (355 μL) was added DIPEA (75 μl, 0.426 mmol) and thenacryloyl chloride (5.2 μl, 0.064 mmol). The reactions were stirred for 5minutes and then concentrated in vacuo. The crude residue was dissolvedin ˜1:1 AcOH:H₂O and purified by reverse phase HPLC using a 10-40%MeCN:H₂O (with 0.1% TFA) gradient on a MAC-MOD 21.2×150 mm ACE C18-PFP 5μm column to afford the desired product as a TFA salt (2.3 mg, 0.006mmol). (m/z): [M+H]⁺ calculated for C₂₁H₂₂N₄O₂ 363.2 found 363.2.

Preparation 13: 5-chloro-3-fluoro-2-hydrazinylpyridine

To a stirring solution of 5-chloro-2,3-difluoropyridine (2.0 g, 13.42mmol) in ethanol (30 mL) was added N₂H₄.H₂O (3.35 mL, 67.11 mmol) andthe reaction was brought to reflux and stirred for 16 h. The reactionwas then cooled and concentrated half the original volume, and thencooled in an ice bath to induce precipitation. The precipitate wasfiltered and washed with a minimal amount of EtOH and water, then driedunder vacuum to obtain the desired product as a white powder (1.9 g,11.76 mmol). (m/z): [M+H]⁺ calculated for C₅H₅ClFN₃163.0 found 163.9.

Preparation 14: 6-chloro-8-fluoro-[1,2,4]triazolo[4,3-a]pyridine

To a stirring solution of 5-chloro-3-fluoro-2-hydrazinylpyridine (1.0 g,6.21 mmol) in triethoxymethane (15 mL) with molecular sieves was addedcatalytic formic acid. The reaction was heated to 100° C. and stirredfor 5 h. The reaction was then cooled and concentrated, and the crudewas triturated with diethyl ether to afford the desired compound as offwhite solid (710 mg, 4.14 mmol). (m/z): [M+H]⁺ calculated for C₆H₃ClFN₃173.0 found 173.0.

Preparation 15: tert-butyl3-(((6-chloro-[1,2,4]triazolo[4,3-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate

To a stirring solution of tert-butyl6-chloro-8-fluoro-[1,2,4]triazolo[4,3-a]pyridine (700 mg, 4.09 mmol) inDMSO (20 mL) was added tert-butyl3-(hydroxymethyl)azetidine-1-carboxylate (919 mg, 4.91 mmol) and Cs₂CO₃(2.66 g, 8.18 mmol) and reaction was heated to 120° C. and stirred for 8h. The reaction was then cooled to room temperature and then partitionedbetween water and EtOAc. The organic layer was isolated, washed withwater and brine, dried over anhydrous Na₂SO₄, filtered, and thenconcentrated to afford the crude product as a viscous liquid (730 mg,2.15 mmol). The product was used without any further purification.(m/z): [M+H]⁺ calculated for C₁₅H₁₉ClN₄O₃ 340.1 found 340.1.

Preparation 16: tert-butyl3-(((6-(4-hydroxyphenyl)-[1,2,4]triazolo[4,3-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate

To a stirring solution of tert-butyl3-(((6-chloro-[1,2,4]triazolo[4,3-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate(700 mg, 2.21 mmol) in DME:EtOH:H₂O (7:2.3:1) (31 mL) was added(4-hydroxyphenyl)boronic acid (341 mg, 2.48 mmol) followed by Na₂CO₃(655 mg, 6.18 mmol). The reaction mixture was sparged with argon for 15min and was followed by the addition of PdCl₂(dppf) (168 mg, 0.20 mmol).The reaction was heated to 120° C. and stirred for 6 h. The reactionmixture was filtered through a pad of celite, the pad was washed withEtOAc, and the filtrate was diluted with H₂O (30 mL). The filtrate wasthen extracted using EtOAc (2×50 mL). The organic layer was washed withwater and dried over Na₂SO₄, filtered, and then concentrated underreduced pressure to obtain the crude product. Purification by neutralalumina chromatography using a 10% MeOH:DCM solvent system afforded thedesired product as an off white solid (400 mg, 1.00 mmol). (m/z): [M+H]⁺calculated for C₂₁H₂₄N₄O₄ 397.1 found 397.1.

Preparation 17:4-(8-(azetidin-3-ylmethoxy)-[1,2,4]triazolo[4,3-a]pyridin-6-yl)phenol

To a stirring solution of tert-butyl3-(((6-(4-hydroxyphenyl)-[1,2,4]triazolo[4,3-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate(350 mg, 0.88 mmol) in DCM (15 mL) was added TFA (2.0 mL). The reactionwas stirred at room temperature for 3 h and was then concentrated underreduced pressure. The residue was triturated with diethyl ether toafford the TFA salt of the desired product as a light brown solid (445mg, 1.50 mmol). (m/z): [M+H]⁺ calculated for C₁₆H₁₆N₄O₂ 297.1 found297.1.

Example 5:1-(3-(((6-(4-hydroxyphenyl)-[1,2,4]triazolo[4,3-a]pyridin-8-yl)oxy)methyl)azetidin-1-yl)prop-2-en-1-one

To a stirring solution of4-(8-(azetidin-3-ylmethoxy)-[1,2,4]triazolo[4,3-a]pyridin-6-yl)phenol(28 mg, 0.069 mmol) in DMF (344 μl) was added DIPEA (72 μl, 0.412 mmol)and then acryloyl chloride (5.3 μl, 0.065 mmol). The reaction was runfor 5 minutes and was then concentrated to dryness in vacuo. The cruderesidue was redissolved in ˜1:1 AcOH:H₂O and purified by reverse phaseHPLC using a 18-45% MeCN:H₂O (with 0.1% TFA) using a Phenomenex 21.2×250mm Luna Axia C18 column to afford the desired product as a TFA salt (7.6mg, 0.022 mmol). (m/z): [M+H]⁺ calculated for C₁₉H₁₈N₄O₃ 351.1 found351.2.

Preparation 18: 3-chloro-5-(4-hydroxyphenyl)pyrazine-2-carbonitrile

To a stirring solution of 3,5-dichloropyrazine-2-carbonitrile (300 mg,1.72 mmol) in dioxane:H₂O (5.0 mL:1.0 mL) was added(4-hydroxyphenyl)boronic acid (261 mg, 1.89 mmol) followed by Cs₂CO₃(1.1g, 3.44 mmol). The reaction mixture was purged with argon for 5 minutesand then PdCl₂(dppf) (140 mg, 0.17 mmol) was added. The reaction wasthen heated to 100° C. and stirred for 3 h. The reaction was then cooledand filtered through a celite pad and the filtrate was concentratedunder reduced pressure to afford the crude product. The crude productwas then purified by silica gel column chromatography using a 10-12%EtOAc:hexanes gradient to afford the desired product (140 mg, 0.60mmol). Regiochemistry was confirmed by NOE analysis. (m/z): [M+H]⁺calculated for C₁₁H₆ClN₃O 233.0 found 233.1.

Preparation 19: tert-butyl3-(((3-cyano-6-(4-hydroxyphenyl)pyrazin-2-yl)oxy)methyl)azetidine-1-carboxylate

In a dry two neck flask charged with NaH (60% dispersion in mineral oil)(134 mg, 3.37 mmol) was added DMF (2.0 mL) at 0° C. Tto this was addedtert-butyl 3-(hydroxymethyl)azetidine-1-carboxylate (637 mg, 3.37 mmol)dissolved in DMF (4.0 mL). The reaction was stirred at 0° C. for 30 minand then 3-chloro-5-(4-hydroxyphenyl)pyrazine-2-carbonitrile (650 mg,2.81 mmol) in DMF (4 mL) was added. The reaction was stirred at 0° C.for 30 min. The reaction was then quenched with ice and extracted withEtOAc. The organic layer was dried over Na₂SO₄, filtered, andconcentrated under reduced pressure to afford the crude product. Thecrude product was purified by silica gel column chromatography using a20-25% EtOAc:hexanes gradient to afford the desired product (610 mg,1.60 mmol). (m/z): [M+H]⁺ calculated for C₂₀H₂₂N₄O₄ 383.1 found 383.1.

Preparation 20: tert-butyl3-(((3-(aminomethyl)-6-(4-hydroxyphenyl)pyrazin-2-yl)oxy)methyl)azetidine-1-carboxylate

In a dry flask charged with Raney Ni (1.0 g) was added tert-butyl3-(((3-cyano-6-(4-hydroxyphenyl)pyrazin-2-yl)oxy)methyl)azetidine-1-carboxylate(400 mg, 1.04 mmol) dissolved in MeOH (20 mL) followed by NH₄OH (10 mL).The reaction was then set under an atmosphere of hydrogen using aballooon. The reaction was stirred at 25° C. for 16 h. The reactionmixture was then filtered through a pad of celite and the filtrate wasconcentrated under reduced pressure to obtain the crude product (380 mg,0.98 mmol). The product was used without any further purification.(m/z): [M+H]⁺ calculated for C₂₀H₂₆N₄O₄ 387.2 found 387.3.

Preparation 21: tert-butyl3-(((3-(formamidomethyl)-6-(4-hydroxyphenyl)pyrazin-2-yl)oxy)methyl)azetidine-1-carboxylate

In a dry, sealed pressure tube, a mixture of HCO₂H (0.53 mL, 14.25 mmol)and Ac₂O (0.87 mL, 9.5 mmol) was heated at 70° C. for 2 h. Theformylating mixture was cooled to room temperature and then added to asolution of tert-butyl3-(((3-(aminomethyl)-6-(4-hydroxyphenyl)pyrazin-2-yl)oxy)methyl)azetidine-1-carboxylate(370 mg, 0.95 mmol) in THF (10 mL) at 0° C. The reaction was stirred atroom temperature for 2 h. The reaction was diluted with water andextracted with ethyl acetate. The organic layer was dried over Na₂SO₄,filtered, and concentrated under reduced pressure to afford the crudeproduct (360 mg, 0.87 mmol). The crude was used in the subsequentreaction with no further purification.

Preparation 22: tert-butyl3-(((6-(4-hydroxyphenyl)imidazo[1,5-a]pyrazin-8-yl)oxy)methyl)azetidine-1-carboxylate

To a stirring solution of tert-butyl3-(((3-(formamidomethyl)-6-(4-hydroxyphenyl)pyrazin-2-yl)oxy)methyl)azetidine-1-carboxylate(360 mg, 0.86 mmol) in DCM (15 mL) was added TFAA (0.36 mL, 2.60 mmol)at 0° C. The reaction was then warmed to room temperature and stirredfor 16 h. The reaction mixture was concentrated under reduced pressureto obtain the crude product which was not purified any further (350 mg,0.89 mmol). (m/z): [M+H]⁺ calculated for C₁₈H₁₅F₃N₄O₃ 393.1 found 393.0.

Preparation 23:4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyrazin-6-yl)phenol

To a stirring solution of2,2,2-trifluoro-1-(3-(((6-(4-hydroxyphenyl)imidazo[1,5-a]pyrazin-8-yl)oxy)methyl)azetidin-1-yl)ethan-1-one(350 mg, 0.89 mmol) in MeOH (15 mL) at 0° C. was added K₂CO₃ (360 mg,2.67 mmol). The reaction was then warmed to room temperature and stirredfor 1 h. The reaction was then concentrated under reduced pressure toobtain the crude product. The crude product was purified by reversephase prep. HPLC to afford the desired product as a TFA salt (90 mg,0.304 mmol). (m/z): [M+H]⁺ calculated for C₁₆H₁₆N₄O₂ 297.1 found 297.0.

Example 6:1-(3-(((6-(4-hydroxyphenyl)imidazo[1,5-a]pyrazin-8-yl)oxy)methyl)azetidin-1-yl)prop-2-en-1-one

To a stirring solution of4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyrazin-6-yl)phenol (28 mg,0.069 mmol) in DMF (344 μl) was added DIPEA (72 μl, 0.412 mmol) and thenacryloyl chloride (5.3 μl, 0.065 mmol). The reaction was run for 5minutes and was then concentrated to dryness in vacuo. The crude residuewas dissolved in ˜1:1 AcOH:H₂O and purified by reverse phase HPLC usinga 18-45% MeCN:H₂O (with 0.1% TFA) using a Phenomenex 21.2×250 mm LunaAxia C18 column to afford the desired product as a TFA salt (11.9 mg,0.034 mmol). (m/z): [M+H]⁺ calculated for C₁₉H₁₈N₄O₃ 351.1 found 351.1.

Preparation 24: methyl 5-bromo-3-fluoropicolinate

To a stirring solution of 5-bromo-3-fluoropicolinonitrile (8.0 g, 39.80mmol) in MeOH (80 mL) was added 4N HCl (80 mL). The reaction was stirredunder reflux for 30 h. The reaction was then concentrated under reducedpressure and the solid residue was neutralized with saturated NaHCO₃ andextracted with ethyl acetate. The organic layer was washed with brine,dried over Na₂SO₄, filtered and concentrated under reduced pressure toobtain the crude product. The crude was purified by flash chromatographyon silica gel using a 8-10% EtOAc:hexane gradient to afford the desiredproduct as a white solid (5.5 g, 23.5 mmol). (m/z): [M+H]⁺ calculatedfor C₇H5BrFNO₂ 234.9 found 234.9.

Preparation 25: (5-bromo-3-fluoropyridin-2-yl)methanol

To a stirring solution of methyl 5-bromo-3-fluoropicolinate (2×8.0 g,34.18 mmol) in MeOH:THF (1:1) (2×400 ml) was added NaBH₄ (2×3.9 g,102.54 mmol) portion wise at 0° C. and then the reaction mixture wasstirred for 2 h at room temperature. The solvent was removed underreduced pressure and the crude residue was diluted with water andextracted with DCM. The organic layer was further washed with water andbrine, dried over Na₂SO₄, filtered, and concentrated under reducedpressure to afford the desired product as a white solid (13.01 g, 63.15mmol). (m/z): [M+H]⁺ calculated for C₆H₅BrFNO 206.9 found 207.0.

Preparation 26: 5-bromo-2-(bromomethyl)-3-fluoropyridine

To a stirring solution of (5-bromo-3-fluoropyridin-2-yl)methanol (13.0g, 63.41 mmol) in DCM (200 ml) was added PBr₃ (36.1 mL, 380.48 mmol)drop wise at 0° C. The reaction mixture was then stirred at roomtemperature for 4 h. The reaction mixture was carefully poured intosaturated NaHCO₃ in small portions and the pH was maintained at about 6.The solution was then extracted with DCM, dried over Na₂SO₄, filtered,and concentrated under reduced pressure. The crude product was thenpurified by silica gel column chromatography using a 10% EtOAc:hexanesgradient to afford the desired product as white solid (12.05 g, 44.81mmol). (m/z): [M+H]⁺ calculated for C₆H₄Br₂FN 266.8 found 267.1.

Preparation 27:2-((5-bromo-3-fluoropyridin-2-yl)methyl)isoindoline-1,3-dione

To a stirring solution of 5-bromo-2-(bromomethyl)-3-fluoropyridine (12.0g, 44.60 mmol) in DMF (100 ml) was added pthalimide (7.21 g, 49.07 mmol)and K₂CO₃ (12.30 g, 89.20 mmol). The reaction was stirred at roomtemperature for 16 h. The reaction was then diluted with water andextracted with ethyl acetate. The organic fractions were combined andwashed with cold water and brine, dried over Na₂SO₄, filtered, andconcentrated to afford the crude product. The crude product was used inthe subsequent reaction without any further purification (15.02 g).(m/z): [M+H]⁺ calculated for C₁₄H₈BrFN₂O₂ 335.9 found 335.9.

Preparation 28: (5-bromo-3-fluoropyridin-2-yl)methanamine

To a stirring solution of2-((5-bromo-3-fluoropyridin-2-yl)methyl)isoindoline-1,3-dione (15.0 g,44.77 mmol) in EtOH (300 ml) was added hydrazine hydrate (6.2 mL, 134.32mmol). The reaction was then stirred at 50° C. for 6 h. The reaction wasthen cooled and concentrated under reduced pressure and dried completelyunder high vacuum. The solid residue was diluted with excess DCM,triturated and filtered through sintered funnel, and the residue waswashed twice with DCM. The filtrate was concentrated under reducedpressure to obtain the desired product as a light brown viscous liquid(9.1 g, 44.34 mmol). (m/z): [M+H]⁺ calculated for C₆H₆BrFN₂ 205.9 found205.8.

Preparation 29: N-((5-bromo-3-fluoropyridin-2-yl)methyl)formamide

In a sealed tube, acetic anhydride (41.4 mL, 439.02 mmol) and formicacid (19.86 mL, 526.8 mmol) was stirred at 70° C. for 2 h to generate aformylating mixture. To a separate flask containing(5-bromo-3-fluoropyridin-2-yl)methanamine (9.0 g, 43.90 mmol) in THF(200 mL) at 0° C. was added the formylating mixture in a dropwisefashion. The reaction was maintained at 0° C. and stirred for 2 h. Thereaction was then diluted with water and extracted with ethyl acetate.The organic layer was dried over Na₂SO₄, filtered, and concentratedunder reduced pressure to afford the desired product as light brownsolid (10.5 g). The crude product was used in the subsequent reactionwith no further purification. (m/z): [M+H]⁺ calculated for C₇H₆BrFN₂O233.9 found 233.9.

Preparation 30: 6-bromo-8-fluoroimidazo[1,5-a]pyridine

To a stirring solution ofN-((5-bromo-3-fluoropyridin-2-yl)methyl)formamide (10.5 g, 45.06 mmol)in DCM (100 mL) was added TFAA (trifluoroacetic anhydride, 20.27 ml,135.1 mmol) at 0° C. dropwise. The reaction was warmed to roomtemperature and stirred for 3 h. The reaction was cooled to 0° C. andslowly quenched with saturated NaHCO₃ and extracted with DCM. Theorganic layer was concentrated under reduced pressure to obtain thecrude product which was purified by silica gel column chromatographyusing a 20-25% EtOAc:hexane gradient to afford the desired product as alight-brown solid (5.05 g, 23.49 mmol). (m/z): [M+H]⁺ calculated forC₇H₄BrFN₂ 215.9 found 215.9.

Preparation 31: tert-butyl3-(((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate

To a stirring solution of 6-bromo-8-fluoroimidazo[1,5-a]pyridine (1.5 g,6.97 mmol) in DMSO (20 mL) was added tert-butyl3-(hydroxymethyl)azetidine-1-carboxylate (1.56 g, 8.37 mmol) and Cs₂CO₃(4.54 g, 13.94 mmol) at room temperature. The reaction was stirred at120° C. for 6 h in a sealed vial. The reaction was diluted with waterand extracted using EtOAc. The combined organic layers were washed withbrine, dried over Na₂SO₄, filtered, and concentrated to obtain the cruderesidue. Purification of the crude by silica gel column chromatographyusing a 30-40% EtOAc:hex gradient afforded the desired product (1.8 g,4.72 mmol). (m/z): [M+H]⁺ calculated for C₁₆H₂₀BrN₃O₃ 383.0 found 382.9.

Preparation 32: 8-(azetidin-3-ylmethoxy)-6-bromoimidazo[1,5-a]pyridine

To a stirring solution of tert-butyl3-(((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate(1.8 g, 4.72 mmol) in DCM (18 mL) was added TFA (9.0 mL) at 0° C. undera nitrogen atmosphere. The reaction mixture was stirred for 2-3 h atroom temperature. The reaction was then concentrated and triturated withdiethyl ether to afford the desired product as a TFA salt (2.2 g, 5.57mmol). (m/z): [M+H]⁺ calculated for C₁₁H₁₂BrN₃O 283.0 found 282.9.

Preparation 33:4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)-3,5-difluorophenol

To a stirring solution of8-(azetidin-3-ylmethoxy)-6-bromoimidazo[1,5-a]pyridine (70 mg, 0.177mmol) in dioxane (1.42 mL) was added(2,6-difluoro-4-hydroxyphenyl)boronic acid (40 mg, 0.230 mmol), followedby a solution of cesium carbonate (174 mg, 0.533 mmol) in water (354μL). The reaction was sealed and heated to 110° C. overnight. Thereactions were concentrated in vacuo and used in the subsequent reactionwithout further purification. (m/z): [M+H]⁺ calculated for C₁₇H₁₅FN₃O₂332.1 found 332.

Example 7:1-(3-(((6-(2,6-difluoro-4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidin-1-yl)prop-2-en-1-one

To a stirring solution of4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)-3,5-difluorophenolin DMF (619 μl) was added DIPEA (130 μl, 0.742 mmol) and then acryloylchloride (5.03 μl, 0.062 mmol). The reaction was stirred for 10 minutesand then concentrated in vacuo. The crude residue was dissolved in ˜1:1AcOH:H₂O and then purified by reverse phase HPLC using a 10-45% MeCN:H₂Ogradient (with 0.1% TFA) using a Phenomenex 21.2×250 mm Luna Axia C18column to afford the desired product as a TFA salt (1.4 mg, 0.004 mmol).(m/z): [M+H]⁺ calculated for C₂₀H₇F₂N₃O₃ 386.1 found 386.1.

Preparation 34:4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)-2,3-difluorophenol

To a stirring solution of8-(azetidin-3-ylmethoxy)-6-bromoimidazo[1,5-a]pyridine (70 mg, 0.177mmol) in dioxane (1.42 mL) was added(2,3-difluoro-4-hydroxyphenyl)boronic acid (40 mg, 0.230 mmol), followedby a solution of cesium carbonate (174 mg, 0.533 mmol) in water (354μL). The reaction was sealed and heated to 110° C. overnight. Thereactions were concentrated in vacuo and used in the subsequent reactionwithout further purification. (m/z): [M+H]⁺ calculated for C₁₇H₁₅FN₃O₂332.1 found 332.

Example 8:1-(3-(((6-(2,3-difluoro-4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidin-1-yl)prop-2-en-1-one

To a stirring solution of4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)-2,3-difluorophenolin DMF (619 μl) was added DIPEA (130 μl, 0.742 mmol) and then acryloylchloride (5.03 μl, 0.062 mmol). The reaction was stirred for 10 minutesand then concentrated in vacuo. The crude residue was dissolved in ˜1:1AcOH:H₂O and then purified by reverse phase HPLC using a 10-50% MeCN:H₂Ogradient (with 0.1% TFA) using a Phenomenex 21.2×250 mm Luna Axia C18column to afford the desired product as a TFA salt (3.3 mg, 0.009 mmol).(m/z): [M+H]⁺ calculated for C₂₀H₁₇F₂N₃O₃ 386.1 found 386.1.

Preparation 35:4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)-2-chloro-6-methoxyphenol

To a stirring solution of8-(azetidin-3-ylmethoxy)-6-bromoimidazo[1,5-a]pyridine (70 mg, 0.177mmol) in dioxane (1.42 mL) was added3-chloro-4-hydroxy-5-methoxyphenylboronic acid (47 mg, 0.230 mmol),followed by a solution of cesium carbonate (174 mg, 0.533 mmol) in water(354 μL). The reaction was sealed and heated to 110° C. overnight. Thereactions were concentrated in vacuo and used in the subsequent reactionwithout further purification. (m/z): [M+H]⁺ calculated for C₁₈H₁₈ClN₃O₃361.1 found 361.2.

Example 9:1-(3-(((6-(3-chloro-4-hydroxy-5-methoxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidin-1-yl)prop-2-en-1-one

To a stirring solution of4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)-2-chloro-6-methoxyphenolin DMF (619 μl) was added DIPEA (130 μl, 0.742 mmol) and then acryloylchloride (5.03 μl, 0.062 mmol). The reaction was stirred for 10 minutesand then concentrated in vacuo. The crude residue was dissolved in ˜1:1AcOH:H₂O and then purified by reverse phase HPLC using a 10-50% MeCN:H₂Ogradient (with 0.1% TFA) using a Phenomenex 21.2×250 mm Luna Axia C18column to afford the desired product as a TFA salt (2.8 mg, 0.007 mmol).(m/z): [M+H]⁺ calculated for C₂₁H₂₀ClN₃O₄ 415.1 found 415.2.

Preparation 36: tert-butyl(1R,3S,5S)-3-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)-8-azabicyclo[3.2.1]octane-8-carboxylate

To a solution of tert-Butyl3-exo-hydroxy-8-azabicyclo[3.2.1]octane-8-carboxylate (149 mg, 0.657mmol) in DMF (2.5 mL) at 0° C. was added potassiumbis(trimethylsilyl)amide solution (1 M in THF) (1.18 mL, 1.183 mmol) andthe reaction was stirred at 0° C. for 10 minutes, 10 minutes at rt, then5 minutes at 0° C. A solution of4-(8-fluoroimidazo[1,5-a]pyridin-6-yl)phenol (100 mg, 0.438 mmol) in DMF(375 uL) was then added to the solution at 0° C. and the black reactionwas heated to 50° C. and stirred for 2 hours. The reaction was quenchedwith 5 mL H₂O and extracted with 3×5 mL EtOAc. The organic extracts werecombined and dried over Na₂SO₄, filtered, and concentrated onto celite.Purification by silica gel column chromatography using a 0-100% gradientyielded the product as an orange solid (79 mg, 0.181 mmol). (m/z):[M+H]⁺ calculated for C₂₉H₂₅N₃O₄ 436.2 found 436.

Preparation 37:4-(8-(((1R,3S,5S)-8-azabicyclo[3.2.1]octan-3-yl)oxy)imidazo[1,5-a]pyridin-6-yl)phenol

To a stirring solution of tert-butyl(1R,3S,5S)-3-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)-8-azabicyclo[3.2.1]octane-8-carboxylate(79 mg, 0.181 mmol) in DCM (500 μL) was added TFA (500 μL). The reactionwas stirred for 2 hours and then concentrated in vacuo to afford thecrude product as a TFA salt. The crude product was used without anyfurther purification and 100% yield was assumed (61 mg, 0.181 mmol).(m/z): [M+H]⁺ calculated for C₂₀H₂₁N₃O₂ 336.2 found 336.

Example 10:1-((1R,3S,5S)-3-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)-8-azabicyclo[3.2.1]octan-8-yl)prop-2-en-1-one

To a stirring solution of4-(8-(((1R,3S,5S)-8-azabicyclo[3.2.1]octan-3-yl)oxy)imidazo[1,5-a]pyridin-6-yl)phenol(61 mg, 0.136 mmol) in DMF (950 μL) was added DIPEA (143 μL, 0.816 mmol)and then acryloyl chloride (8.84 μL, 0.015 mmol). The reaction wasstirred for 5 minutes and concentrated in vacuo. The crude residue wasdissolved in ˜1:1 AcOH:H₂O and purified by reverse phase HPLC using a10-50% MeCN:H₂O gradient (with 0.1% TFA) using a Phenomenex 21.2×250 mmLuna Axia C18 column to afford the desired product as a TFA salt (12 mg,0.031 mmol). (m/z): [M+H]⁺ calculated for C₂₃H₂₃N₃O₃ 390.2 found 390.0.

Preparation 38: tert-butyl3-(((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate

To a solution of tert-butyl 3-(hydroxymethyl)azetidine-1-carboxylate(1.22 g, 6.51 mmol) in DMF (15 mL) at 0° C. was added sodium hydride(60% dispersion in mineral oil) (279 mg, 6.98 mmol) and the reaction waswarmed to room temperature and stirred for 30 minutes. The alkoxidesuspension was then added dropwise to a stirring solution of4-(8-fluoroimidazo[1,5-a]pyridin-6-yl)phenol (50 mg, 0.219 mmol) in DMF(8.25 mL) and the resulting reaction was warmed to room temperature andstirred for 24 hours. The reaction was quenched with 60 mL H₂O andextracted with 3×25 mL EtOAc. The organic extracts were combined, driedover Na₂SO₄, filtered, and concentrated onto celite. The crude materialwas purified by silica gel column chromatography using a 0-80%EtOAc:hexanes gradient to afford the product as a white solid (1.48 g,3.87 mmol). (m/z): [M+H]⁺ calculated for C₁₁H₁₂BrN₃O 383.0 found 382.9.

Preparation 39: tert-butyl3-(((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate

To a solution of tert-butyl3-(((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate(889 mg, 2.33 mmol) in dioxane (9.3 mL) was added(4-hydroxyphenyl)boronic acid (385 mg, 2.79 mmol), potassium phosphate,tribasic (1481 mg, 6.98 mmol) in water (2.3 mL), anddichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium (ii)dichloromethane adduct (380 mg, 0.465 mmol). The vial was sealed andheated to 110° C. for 18 hours. The reaction was then cooled andconcentrated onto celite in vacuo to afford the crude product. The crudeproduct was then purified by silica gel column chromatography using a10-100% EtOAc:Hex gradient to afford the desired product. (m/z): [M+H]⁺calculated for C₂₂H₂₅N₃O₄ 396.2 found 396.0.

Preparation 40:4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)phenol

To a solution of tert-butyl3-(((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate(671 mg, 1.697 mmol) in DCM (5.0 ml) was added TFA (2.500 ml) and thereaction was stirred for 1 hour. The reaction was then concentrateddirectly in vacuo and dried overnight on high vacuum to afford the crudeproduct that was not purified any further. (m/z): [M+H]⁺ calculated forC₁₇H₁₇N₃O₂ 296.1 found 295.9.

Example 11:1-(3-(((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidin-1-yl)prop-2-en-1-one

To a stirring solution of4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)phenol (39 mg,0.095 mmol) in DMF (475 μL) was added DIPEA (83 μL, 0.475 mmol) and thenacryloyl chloride (7.7 μL, 0.095 mmol). The reaction was stirred for 5minutes and concentrated in vacuo. The crude residue was dissolved in˜1:1 AcOH:H₂O and purified by reverse phase HPLC using a 5-45% MeCN:H₂Ogradient (with 0.1% TFA) using a Phenomenex 21.2×250 mm Luna Axia C18column to afford the desired product as a TFA salt (2.4 mg, 0.007 mmol).(m/z): [M+H]⁺ calculated for C₂₀H₁₉N₃O₃ 350.1 found 350.1. ¹H NMR (400MHz, DMSO-d₆) δ 9.19 (s, 1H), 8.37 (s, 1H), 7.85 (s, 1H), 7.55 (d, J=8.5Hz, 2H), 6.88 (d, J=8.5 Hz, 2H), 6.80 (s, 1H), 6.32 (dd, J=16.9, 10.2Hz, 1H), 6.10 (dd, J=16.9, 1.8 Hz, 1H), 5.65 (dd, J=10.3, 1.8 Hz, 1H),4.47 (d, J=6.4 Hz, 2H), 4.38 (t, J=8.6 Hz, 1H), 3.79 (dd, J=10.1, 5.3Hz, 1H).

Preparation 41: tert-butyl3-(((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate

To a solution of tert-butyl 3-(hydroxymethyl)azetidine-1-carboxylate(1.22 g, 6.51 mmol) in DMF (15 mL) at 0° C. was added sodium hydride(60% dispersion in mineral oil) (279 mg, 6.98 mmol) and the reaction waswarmed to room temperature and stirred for 30 minutes. The alkoxidesuspension was then added dropwise to a stirring solution of4-(8-fluoroimidazo[1,5-a]pyridin-6-yl)phenol (50 mg, 0.219 mmol) in DMF(8.25 mL) and the resulting reaction was warmed to room temperature andstirred for 24 hours. The reaction was quenched with 60 mL H₂O andextracted with 3×25 mL EtOAc. The organic extracts were combined, driedover Na₂SO₄, filtered, and concentrated onto celite. The crude materialwas purified by silica gel column chromatography using a 0-80%EtOAc:hexanes gradient to afford the product as a white solid (1.48 g,3.87 mmol). (m/z): [M+H]⁺ calculated for C₁₁H₁₂BrN₃O 283.0 found 282.9.

Preparation 42: tert-butyl3-(((6-(3-chloro-4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate

To a stirring solution of tert-butyl3-(((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate(370 mg, 0.968 mmol) in dioxane (5.16 mL) was added a solution ofpotassium phosphate, tribasic (616 mg, 2.90 mmol) in water (1.29 mL),dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium (158 mg, 0.194mmol), and 3-chloro-4-hydroxyphenylboronic acid (200 mg, 1.16 mmol). Thevial was sealed, heated to 110° C., and stirred for 18 hours. Thereaction was then cooled to room temperature and concentrated ontocelite. The crude material was purified by silica gel columnchromatography using a 10-100% EtOAc:hexane gradient to afford thedesired product (143 mg, 0.333 mmol). (m/z): [M+H]⁺ calculated forC₂₂H₂₄ClN₃O₄ 431.1 found 431.1.

Preparation 43:4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)-2-chlorophenol

To a stirring solution of tert-butyl tert-butyl3-(((6-(3-chloro-4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate(143 mg, 0.333 mmol) in DCM (500 μL) was added TFA (500 μL). Thereaction was stirred for 2 hours and then concentrated in vacuo toafford the crude product as a TFA salt. The crude product was usedwithout any further purification and 100% yield was assumed (110 mg,0.333 mmol). (m/z): [M+H]⁺ calculated for C₁₇H₁₆ClN₃O₂ 331.0 found331.2.

Example 12:1-(3-(((6-(3-chloro-4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidin-1-yl)prop-2-en-1-one

To a solution of4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)-2-chlorophenol(110 mg, 0.333 mmol) in DMF (1.0 mL) was added DIPEA (192 μl, 1.097mmol) and then acryloyl chloride (16.1 μl, 0.198 mmol) dropwise. Thereaction was stirred for 5 minutes and then concentrated in vacuo. Thecrude material was dissolved in ˜1:1 AcOH:H₂O and purified using a10-50% MeCN:H₂O (with 0.1% TFA) gradient on a Phenomenex 21.2×250 mmLuna Axia C18 column to afford the desired product as a TFA salt (8.6mg, 0.022 mmol). (m/z): [M+H]⁺ calculated for C₂₀H₁₈ClN₃O₃ 385.1 found385.2.

Preparation 44: tert-butyl3-(((6-(2-ethyl-5-fluoro-4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate

To a stirring solution of tert-butyl3-(((6-bromoimidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate(370 mg, 0.968 mmol) in dioxane (5.16 mL) was added a solution ofpotassium phosphate, tribasic (616 mg, 2.90 mmol) in water (1.29 mL),dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium (158 mg, 0.194mmol), and 3-fluoro-4-hydroxyphenylboronic acid (181 mg, 1.16 mmol). Thevial was sealed, heated to 110° C., and stirred for 18 hours. Thereaction was then cooled to room temperature and concentrated ontocelite. The crude material was purified by silica gel columnchromatography using a 10-100% EtOAc:hexane gradient to afford thedesired product (274 mg, 0.621 mmol). (m/z): [M+H]⁺ calculated forC₂₄H₂₈FN₃O₄ 442.2 found 442.

Preparation 45:4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)-5-ethyl-2-fluorophenol

To a stirring solution of tert-butyl3-(((6-(2-ethyl-5-fluoro-4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidine-1-carboxylate (274 mg,0.621 mmol) in DCM (500 μL) was added TFA (500 μL). The reaction wasstirred for 2 hours and then concentrated in vacuo to afford the crudeproduct as a TFA salt. The crude product was used without any furtherpurification and 100% yield was assumed (212 mg, 0.621 mmol). (m/z):[M+H]⁺ calculated for C₁₇H₁₆ClN₃O₂ 342.1 found 342.

Example 13:1-(3-(((6-(2-ethyl-5-fluoro-4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)methyl)azetidin-1-yl)prop-2-en-1-one

To a solution of4-(8-(azetidin-3-ylmethoxy)imidazo[1,5-a]pyridin-6-yl)-5-ethyl-2-fluorophenol(100 mg, 0.219 mmol) in DMF (1.1 mL) was added DIPEA (192 μl, 1.097mmol) and then acryloyl chloride (16.1 μl, 0.198 mmol) dropwise. Thereaction was stirred for 5 minutes and then concentrated in vacuo. Thecrude material was dissolved in ˜1:1 AcOH:H₂O and purified using a10-50% MeCN:H₂O (with 0.1% TFA) gradient on a Phenomenex 21.2×250 mmLuna Axia C18 column to afford the desired product as a TFA salt (2.1mg, 0.005 mmol). (m/z): [M+H]⁺ calculated for C₂₂H₂₂FN₃O₃ 396.16 found396.1.

Preparation 46: tert-butyl3,3-difluoro-4-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)piperidine-1-carboxylate

To a stirring solution of tert-butyl3,3-difluoro-4-hydroxypiperidine-1-carboxylate in DMF (1.64 mL) at 0° C.was added potassium hexamethyldisilazide (1.0 M in THF) (1775 μl, 1.775mmol) and the reactions were warmed to room temperature and stirred for20 minutes. The alkoxide solution was cooled to 0° C. and a solution of4-(8-fluoroimidazo[1,5-a]pyridin-6-yl)phenol (150 mg, 0.657 mmol) wasadded. The resulting reaction was stirred at room temperature for 3hours, then diluted with 10 mL H₂O and extracted with 3×5 mL EtOAc. Theorganic extracts were combined and dried over Na₂SO₄, filtered, andconcentrated onto celite. Purification by silica gel columnchromatography using a 10-100% EtOAc:hexanes gradient yielded thedesired product (176 mg, 0.394 mmol). (m/z): [M+H]⁺ calculated forC₂₃H₂₅F₂N₃O₄ 446.1 found 446.

Preparation 47:4-(8-((3,3-difluoropiperidin-4-yl)oxy)imidazo[1,5-a]pyridin-6-yl)phenol

To a stirring solution of tert-butyl3,3-difluoro-4-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)piperidine-1-carboxylate (176 mg, 0.394mmol) in DCM (500 μL) was added TFA (500 μL). The reaction was stirredfor 2 hours and then concentrated in vacuo to afford the crude productas a TFA salt. The crude product was used without any furtherpurification and 100% yield was assumed (136 mg, 0.394 mmol). (m/z):[M+H]⁺ calculated for C₁₈H₁₇F₂N₃O₂ 346.1 found 346.

Example 14:1-(3,3-difluoro-4-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)piperidin-1-yl)prop-2-en-1-one

To a solution of4-(8-((3,3-difluoropiperidin-4-yl)oxy)imidazo[1,5-a]pyridin-6-yl)phenol(136 mg, 0.395 mmol) in DMF (1.98 mL) was added DIPEA (414 μl, 2.37mmol) and then acryloyl chloride (24.1 μl, 0.296 mmol) dropwise. Thereaction was stirred for 5 minutes and then concentrated in vacuo. Thecrude material was dissolved in ˜1:1 AcOH:H₂O and purified using a20-35% MeCN:H₂O (with 0.1% TFA) gradient on a Phenomenex 21.2×250 mmLuna Axia C18 column to afford the desired product as a TFA salt (5.6mg, 0.014 mmol). (m/z): [M+H]⁺ calculated for C₂₁H₁₉F₂N₃O₃ 400.1 found400.1.

Preparation 48: tert-butyl(2R,4R)-4-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)-2-methylpiperidine-1-carboxylate

To a stirring solution of tert-butyl(2R,4R)-4-hydroxy-2-methylpiperidine-1-carboxylate (170 mg, 0.789 mmol)in DMF (1.3 mL) was added KHMDS (1.0 M in THF) (1.42 mL, 1.42 mmol). Asolution of 4-(8-fluoroimidazo[1,5-a]pyridin-6-yl)phenol (120 mg, 0.526mmol) in DMF (1.3 mL) was then added to the potassium alkoxide solution.The reaction was stirred at 50° C. for 2 h and then cooled to roomtemperature. The reaction mixture was diluted with H₂O (10 mL) andextracted with 3×5 mL EtOAc. The organic layer was dried over Na₂SO₄,filtered, and concentrated onto celite. Purification by silica gelcolumn chromatography using a 0-100% EtOAc:hexanes gradient afforded thedesired product (49 mg, 0.116 mmol). (m/z): [M+H]⁺ calculated forC₂₄H₂₉N₃O₄ 424.2 found 424.2.

Preparation 49:tert-butyl(2R,4R)-4-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)-2-methylpiperidine-1-carboxylate

To a stirring solution of tert-butyl(2R,4R)-4-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)-2-methylpiperidine-1-carboxylatein DCM (1.0 mL) was added TFA (1.0 mL) and the reaction was stirred atroom temperature for 2 h. The reactions were then concentrated underreduced pressure to afford the desire product as a TFA salt (51 mg,0.116 mmol). The crude product was used without any furtherpurification. (m/z): [M+H]⁺ calculated for C₁₉H₂₁N₃O₂ 324.1 found 324.2.

Example 15:1-((2R,4R)-4-((6-(4-hydroxyphenyl)imidazo[1,5-a]pyridin-8-yl)oxy)-2-methylpiperidin-1-yl)prop-2-en-1-one

To a solution of4-(8-(((2R,4R)-2-methylpiperidin-4-yl)oxy)imidazo[1,5-a]pyridin-6-yl)phenol(51 mg, 0.117 mmol) in DMF (585 μL) was added DIPEA (123 μL, 0.702 mmol)and then acryloyl chloride (7.6 μl, 0.094 mmol) dropwise. The reactionwas stirred for 5 minutes and then concentrated in vacuo. The crudematerial was dissolved in ˜1:1 AcOH:H₂O and purified using a 10-50%MeCN:H₂O (with 0.1% TFA) gradient on a Phenomenex 21.2×250 mm Luna AxiaC18 column to afford the desired product as a TFA salt (7.8 mg, 0.021mmol). (m/z): [M+H]⁺ calculated for C₂₂H₂₃N₃O₃ 478.1 found 478.0.

Compounds 16 to 52 in Table 1 were prepared by similar synthetic methodsusing the appropriate starting materials.

TABLE 1 Calculated Found Ex No. Structure [M + H]⁺ [M + H]⁺ 16

410.17 410.0 17

377.18 377.1 18

467.23 467.0 19

407.19 407.2 20

368.13 368.1 21

378.17 378.2 22

425.18 425.2 23

441.15 441.1 24

453.21 453.2 25

435.22 435.2 26

364.15 364.2 27

364.15 364.1 28

378.17 378.1 29

366.11 366.1 30

364.15 364.1 31

402.09 402.0 32

386.12 386.1 33

148.06 418.0 34

364.15 364.1 35

378.17 378.1 36

390.17 390.1 37

376.15 376.1 38

378.17 378.0 39

378.17 378.1 40

392.18 392.1 41

378.17 378.1 42

418.12 418.0 43

378.17 378.0 44

364.15 364.0 45

380.15 380.0 46

422.17 422.2 47

410.17 410.2 48

436.19 436.1 49

446.15 446.1 50

389.17 389.2 51

363.16 363.2 52

349.39 349.2

Biological Assays

The compounds of the disclosure have been characterized in one or moreof the following biological assays.

Assay 1: Biochemical JAK and Tyk2 Kinase Assays

A panel of four LanthaScreen JAK biochemical assays (JAK1, 2, 3 andTyk2) were carried in a common kinase reaction buffer (50 mM HEPES, pH7.5, 0.01% Brij-35, 10 mM MgCl₂, and 1 mM EGTA). Recombinant GST-taggedJAK enzymes and a GFP-tagged STAT1 peptide substrate were obtained fromLife Technologies.

Serially or discretely diluted compounds were pre-incubated with each ofthe four JAK enzymes and the substrate in white 384-well microplates(Corning) at ambient temperature for 1 h. ATP was subsequently added toinitiate the kinase reactions in 10 μL total volume, with 1% DMSO. Thefinal enzyme concentrations for JAK1, 2, 3 and Tyk2 are 4.2 nM, 0.1 nM,1 nM, and 0.25 nM respectively; the corresponding Km ATP concentrationsused are 25 μM, 3 μM, 1.6 μM, and 10 μM; while the substrateconcentration is 200 nM for all four assays. Kinase reactions wereallowed to proceed for 1 hour at ambient temperature before a 10 μLpreparation of EDTA (10 mM final concentration) and Tb-anti-pSTAT1(pTyr701) antibody (Life Technologies, 2 nM final concentration) inTR-FRET dilution buffer (Life Technologies) was added. The plates wereallowed to incubate at ambient temperature for 1 h before being read onthe EnVision reader (Perkin Elmer). Emission ratio signals (520 nm/495nm) were recorded and utilized to calculate the percent inhibitionvalues based on DMSO and background controls.

For dose-response analysis, percent inhibition data were plotted vs.compound concentrations, and IC₅₀ values were determined from a4-parameter robust fit model with the Prism software (GraphPadSoftware). Results were expressed as pIC₅₀ (negative logarithm of IC₅₀)and subsequently converted to pKi (negative logarithm of dissociationconstant, Ki) using the Cheng-Prusoff equation.

Assay 2: Cellular JAK3 Potency Assay: Inhibition of IL-2 StimulatedpSTAT5 in Tall-1 T Cells

The potency of test compounds for inhibition of interleukin-2 (IL-2)stimulated STAT5 phosphorylation was measured in the Tall-1 human T cellline (DSMZ) using AlphaLisa. Because IL-2 signals through JAK3, thisassay provides a measure of JAK3 cellular potency.

Phosphorylated STAT5 was measured via the AlphaLISA SureFire UltrapSTAT5 (Tyr694/699) kit (PerkinElmer).

Human T cells from the Tall-1 cell line were cultured in a 37° C., 5%CO₂ humidified incubator in RPMI (Life Technologies) supplemented with15% Heat Inactivated Fetal Bovine Serum (FBS, Life Technologies), 2 mMGlutamax (Life Technologies), 25 mM HEPES (Life Technologies) and1×Pen/Strep (Life Technologies). Compounds were serially diluted in DMSOand dispensed acoustically to empty wells. Assay media (phenol red-freeDMEM (Life Technologies) supplemented with 10% FBS (ATCC)) was dispensed(4 μL/well) and plates shaken at 900 rpm for 10 inns. Cells were seededat 45,000 cells/well in assay media (4 μL/well), and incubated at 37°C., 5% CO₂ for 1 hour, followed by the addition of IL-2 (R&D Systems;final concentration 300 ng/ml) in pre-warmed assay media (4 μL) for 30minutes. After cytokine stimulation, cells were lysed with 6 ul of 3×AlphaLisa Lysis Buffer (PerkinElmer) containing 1× PhosStop and Completetablets (Roche). The lysate was shaken at 900 rpm for 10 minutes at roomtemperature (RT). Phosphorylated STAT5 was measured via the pSTAT5AlphaLisa kit (PerkinElmer). Freshly prepared acceptor bead mixture wasdispensed onto lysate (5 μL) under green filtered <100 lux light. Plateswere shaken at 900 rpm for 2 mins, briefly spun down, and incubated for2 hrs at RT in the dark. Donor beads were dispensed (5 μL) under greenfiltered <100 lux light. Plates were shaken at 900 rpm for 2 minutes,briefly spun down, and incubated overnight at RT in the dark.Luminescence was measured with excitation at 689 nm and emission at 570nm using an EnVision plate reader (PerkinElmer) under green filtered<100 lux light.

To determine the inhibitory potency of test compounds in response toIL-2, the average emission intensity of beads bound to pSTAT5 wasmeasured in a human T cell line. IC₅₀ values were determined fromanalysis of the inhibition curves of signal intensity versus compoundconcentration. Data are expressed as pIC₅₀ (negative decadic logarithmIC₅₀) values (mean standard deviation).

Assay 3: Inhibition of IL-2 Stimulated pSTAT5 in CD4+ T Cells Isolatedfrom Murine Splenocytes

The potency of test compounds for inhibition of interleukin-2 (IL-2)stimulated STAT5 phosphorylation was measured in the CD4+ T cellsisolated from murine splenocytes using AlphaLisa. Because IL-2 signalsthrough JAK3, this assay provides a measure of JAK3 cellular potency inmouse.

Phosphorylated STAT5 was measured via the AlphaLISA SureFire UltrapSTAT5 (Tyr694/699) kit (PerkinElmer).

CD4+ T cells were isolated from murine splenocytes via negativeselection on a magnetic column (Miltnyi Biotec) and re-suspended inassay media (phenol red-free DMEM (Life Technologies) supplemented with10% FBS (ATCC)). Cells were seeded at 50,000 cells/well in assay media(2 μL/well). Compounds were serially diluted in DMSO and diluted to 2×final concentration in assay media. Compound was added (4 μl/well) andthe cells incubated at 37° C., 5% CO₂ for 1 hour, followed by theaddition of IL-2 (R&D Systems; final concentration 7 ng/ml) inpre-warmed assay media (2 μL) for 30 minutes. After cytokinestimulation, cells were lysed with 2 μl of 5× AlphaLisa Lysis Buffer(PerkinElmer). The lysate was shaken at 900 rpm for 10 minutes at roomtemperature (RT). Phosphorylated STAT5 was measured via the pSTAT5AlphaLisa kit (PerkinElmer). Freshly prepared acceptor bead mixture wasdispensed onto lysate (5 ul) under green filtered <100 lux light. Plateswere shaken at 900 rpm for 2 mins, briefly spun down, and incubated for2 hrs at RT in the dark. Donor beads were dispensed (5 μl) under greenfiltered <100 lux light. Plates were shaken at 900 rpm for 2 mins,briefly spun down, and incubated overnight at RT in the dark.Luminescence was measured with excitation at 689 nm and emission at 570nm using an EnVision plate reader (PerkinElmer) under green filtered<100 lux light.

To determine the inhibitory potency of test compounds in response toIL-2, the average emission intensity of beads bound to pSTAT5 wasmeasured in primary CD4+ T cells isolated from murine splenocytes. IC₅₀values were determined from analysis of the inhibition curves of signalintensity vs compound concentration. Data are expressed as pIC₅₀(negative decadic logarithm IC₅₀) values (mean standard deviation).

Compounds 7, 8, 9, 11, 12, 13, 15, 20, 24, 28, 31, and 34 all had pIC₅₀values over 6.0 in this assay.

Assay 4: JAK Cytotoxicity Assay

A CellTiter-Glo luminescent cell viability/cytotoxicity assay wascarried out in BEAS-2B human lung epithelial cells (ATCC) under thenormal growth condition.

Cells were grown at 37° C. in a 5% CO₂ humidified incubator in 50%DMEM/50% F-12 medium (Life Technologies) supplemented with 10% FBS(Hyclone), 100 U/mL penicillin, 100 μg/mL streptomycin (LifeTechnologies), and 2 mM GlutaMAX (Life Technologies). On day 1 of theassay, cells were seeded at a 500 cells/well density in white 384-welltissue culture plates (Corning) with 25 μL medium, and were allowed toadhere overnight in the incubator. On day 2 of the assay, 5 μL of mediumcontaining dose-responses of test compounds was added, and incubated at37° C. for 48 h. 30 μL of CellTiter-Glo detection solution (Promega) wassubsequently added, mixed on an orbital shaker for 5 min, and incubatedfor additional 10 min before being read on the EnVision reader.Luminescence signals were recorded and percent DMSO control values werecalculated.

For dose-response analysis, percent DMSO control data were plotted vs.compound concentrations to derive dose-response curves by lineconnecting each data point. The concentration at which each curvecrosses the 15% inhibition threshold is defined as CC₁₅. Results wereexpressed as the negative logarithm of the CC₁₅ value, pCC₁₅.

It is expected that test compounds exhibiting a lower pCC₁₅ value inthis assay have less likelihood to cause cytotoxicity. Compounds of thedisclosure tested in this assay typically exhibited pCC₁₅ values between5 and about 6.

Assay 5: Caco-2 Permeation Assay

The Caco-2 permeation assay was performed to model the ability of testcompounds to pass through the intestine and get into the blood streamafter oral administration. The rate at which test compounds in solutionpermeate a cell monolayer designed to mimic the tight junction of humansmall intestinal monolayers was determined.

CacoReady 24-well transwell plates were obtained from ADMEcell (Alameda,Calif.). The compounds were evaluated at a concentration of 5 μM from 10mM DMSO stock solutions in duplicate (n=2). The passive permeability ofthe compounds tested was evaluated using Caco-2 cell monolayers alongwith Verapamil (25 μM) to inhibit P-gp transport proteins in the apicalto basolateral (A-B) direction. The experiment was conducted in a 37°C., 5% CO₂ incubator. Caco-2 culture media consisted of standardfiltered DMEM, FCS 10%, L-Glutamine 1% and PenStrep 1%. Basal assayplate was prepared by adding 750 μL of transport buffer to A-B wells. ACacoReady™ plate was prepared by removing the Caco-2 media from theapical wells and replacing with fresh transport media (200 μL repeatedfor a total of 3 washes). Blank media (200 μL) was then replaced withdiluted compound for A-B wells. To begin the incubation, the basal platewas removed from the incubator and the apical section was added on topof it. Samples (40 μL) were collected from the apical and basalcompartments for time zero (t0). Samples were collected again after 120minutes (t120) from the apical and basal compartments. All samples werediluted and prepared for bioanalysis by LC-MS/MS. The permeationcoefficient (K_(p), mean A to B+Verapamil Papparent) in cm/sec wascalculated as dQ (flux)/(dt×Area×concentration).

In this assay, a K_(p) value less than approximately 5×10⁻⁶ cm/sec isconsidered favorable to minimize systemic exposure and target the colon.A K_(p) value less than approximately 10×10⁻⁶ cm/sec may also besufficient to minimize systemic exposure and target the colon. Bycomparison, PF-06651600, a JAK3 inhibitor available systemically(2-propen-1-one,1-[(2S,5R)-2-methyl-5-(7H-pyrrolo[2,3-d]pyrimidin-4-ylamino)-1-piperidinyl])exhibited a K_(p) value of 25.

In Vitro Assay Results

All of the compounds of Examples 1 to 52 were tested in one or more ofthe assays described above.

In Table 2 below, for the JAK1, JAK 2, JAK3, and TYK2 enzyme assays, Arepresents a pK_(i) value ≥10 (K_(i)≤0.1 nM), B represents a pK_(i)value between 9 and 10 (K_(i) between 1 nM and 0.1 nM), C represents apK_(i) value between 8 and 9 (K_(i) between 10 nM and 1 nM), Drepresents a pK_(i) value between 7 and 8 (K_(i) between 100 nM and 10nM), and E represents a pK_(i) value of 7 or below (K_(i) of 100 nM orabove). For the Tall-1 Potency assay, A represents a pIC₅₀ value >7.5(IC₅₀<32 nM), B represents a pIC₅₀ value between 6.7 (included) and 7.5(IC₅₀ between 200 nM and 32 nM), and C represents a PIC₅₀ value between6 and 6.7 (IC₅₀ between 1 and 200 nM). For the JAK3 (pKi)-JAK1(pKi)values, A represents a value of 3 or above, B represents a value of2.3 to 3 and C represents a value of 1.8 to 2.3. For the Caco assay, Arepresents a value below 5×10⁶ cm/se, B represents a value between5×10⁻⁶ and 10×10⁶ cm/see, C represents a value between 10×10⁻⁶ and25×10⁻⁶ cm/sec.

TABLE 2 JAK 1 JAK 2 JAK 3 Tyk 2 Tall-1 JAK3 (pKi)- Caco K_(p) Ex No.(pKi) (pKi) (pKi) (pKi) (pIC₅₀) JAK1 (pKi) 10⁻⁶ cm/sec 1 E E B E C A 2 EE B E C A C 3 E E B E B A 4 E E C E B 5 E A C A 6 E E B E B A B 7 E E BE B A B 8 E E A E B A B 9 E E B E B A A 10 E E A E B A 11 E E B E B A A12 E E B E B A A 13 E E B E A A A 14 E D A E A A B 15 E D A E A A 16 D DB E B B C 17 E C B 18 E B B 19 E B C A 20 E E B E B A A 21 E E B E B A B22 E B C A 23 E E B E C A 24 E E A E B A A 25 E B C A 26 E E B E C A 27E E B E C A 28 E E A E B A A 29 E B C A 30 E E A E B A C 31 E E A E B AA 32 E B C A 33 E A B A A 34 E E B E B A B 35 E B C A 36 E A B A 37 E EB E C A 38 E B B A 39 E E A E B A 40 E C C B 41 E E A E B A 42 E B C A43 E B B A 44 E E B E B A 45 E B C A 46 E B B B 47 D A A B 48 D A A A 49D 10 A C 50 E C B 51 E C B 52 E C B

Assay 6: Colon and Plasma Mouse Pharmacokinetics

6 male Balb/c mice were administered 10 mg/kg of compound in 1%HPMC+0.1% Tween-80 by PO administration. At 0.5, 2 and 6 hours afterdose administration, animals were anesthetized, and terminal bloodsamples were collected by cardiac puncture, followed by collection ofcolon contents and colon tissue.

Blood samples were collected into K₂EDTA and stored on wet ice untilprocessed to plasma by centrifugation (12,000 rpm at 4° C.). Plasmasamples were transferred to cluster tubes and placed on dry ice prior tofreezer storage. The colon contents from each animal were collected ateach terminal blood collection time point. The colon tissues wereflushed with saline and patted dry. The colon and colon content tissueswere homogenized using sterile water containing 0.1% formic acid 9:1(water:tissue, v/w). The homogenized tissues and colon contents weretransferred to cluster tubes and placed on dry ice prior to freezerstorage. All samples were analyzed using LC/MS/MS against analyticalstandards.

The composite pharmacokinetic parameters of the compounds weredetermined by non-compartmental analysis using Phoenix WinNonlin Version6 (Certara, St. Louis, Mo.) and using mean values from 2 animals/timepoint. For plasma concentrations below the quantification limit (BQL),the lowest concentration measurable or the BLOQ (below limit ofquantification) was used.

A colon to plasma ratio was determined as the ratio of the colon AUC tothe plasma AUC. Compounds 12, 13, 16, and 24 exhibited a colon to plasmaratio in excess of 200. Compound 15 exhibited a colon to plasma ratio inexcess of 30. Compound 30 exhibited a colon to plasma ratio in excess of8.

In contrast, the reference compound (PF-06651600, a JAK3 inhibitoravailable systemically) 2-propen-1-one,1-[(2S,5R)-2-methy-5-(7H-pyrrolo[2,3-d]pyrimidin-4-ylamino)-1-piperidinyl],exhibited a colon to plasma ratio of 2.8

While the present invention has been described with reference tospecific aspects or embodiments thereof, it will be understood by thoseof ordinary skilled in the art that various changes can be made orequivalents can be substituted without departing from the true spiritand scope of the invention. Additionally, to the extent permitted byapplicable patent statutes and regulations, all publications, patentsand patent applications cited herein are hereby incorporated byreference in their entirety to the same extent as if each document hadbeen individually incorporated by reference herein.

1-32. (canceled)
 33. A method of treating a gastrointestinalinflammatory disease in a mammal, the method comprising administering tothe mammal a compound of formula (I):

or a pharmaceutically acceptable salt thereof, wherein X¹ and X² areeach independently selected from N and CH;

is selected from the group consisting of

R^(a), R^(b), R^(c), and R^(f) are each independently selected from thegroup consisting of H and C₁₋₃ alkyl; R^(d), R^(e), R^(g), R^(h), R^(i),R^(j), R^(l), R^(m), R^(n) and R^(o) are each independently selectedfrom the group consisting of H and C₁₋₃ alkyl wherein the C₁₋₃ alkylgroup may be optionally substituted with 1 to 3 halogens; A is selectedfrom the group consisting of (a) a 4 to 8 membered monocyclicheterocyclic group containing one nitrogen atom and optionallycontaining one additional heteroatom selected from N, S, S(O)₂ and O,and (b) a 6 to 10 membered multicyclic heterocyclic group containing onenitrogen atom and optionally containing one additional heteroatomselected from N, S, S(O)₂ and O, wherein L is linked to a carbon atom inA and A is optionally substituted with 1 to 3 R^(k) groups; each R^(k)is independently selected from the group consisting of F, CN, C₁₋₃alkoxy, and C₁₋₃ alkyl, wherein the C₁₋₃ alkyl group may be optionallysubstituted with OH, OMe or 1 to 3 halogens; R¹ is selected from thegroup consisting of:

wherein R^(p) and R^(q) are each independently selected from the groupconsisting of H, C₃₋₅ cycloalkyl and C₁₋₆ alkyl; R² is selected from thegroup consisting of H, Cl, OMe, Me and F; R³ is selected from the groupconsisting of H, Me, Et, CF₃, OMe, and F; R⁴ is selected from the groupconsisting of H, Me, OMe, Cl, and F; and R⁵ is selected from the groupconsisting of H, Me, Et, and F, and a pharmaceutically-acceptablecarrier.
 34. The method of claim 33, wherein the gastrointestinalinflammatory disease is selected from the group consisting of immunecheckpoint inhibitor induced colitis, CTLA-4 inhibitor-induced colitis,graft versus host disease-related colitis, celiac disease, collagenouscolitis, lymphocytic colitis, Behcet's disease, ileitis, eosinophilicesophagitis, and infectious colitis.
 35. The method of claim 33, whereinthe gastrointestinal inflammatory disease is ulcerative colitis.
 36. Themethod of claim 33, wherein the gastrointestinal inflammatory disease isCrohn's disease.
 37. The method of claim 33, wherein thegastrointestinal inflammatory disease is celiac disease.
 38. A method oftreating an inflammatory skin disease in a mammal, the method comprisingapplying a pharmaceutical composition comprising a compound of formula(I):

or a pharmaceutically acceptable salt thereof, wherein X¹ and X² areeach independently selected from N and CH:

is selected from the group consisting of

R^(a), R^(b), R^(c), and R^(f) are each independently selected from thegroup consisting of H and C₁₋₃ alkyl; R^(d), R^(e), R^(g), R^(h), R^(i),R^(j), R^(l), R^(m), R^(n), and R^(o) are each independently selectedfrom the group consisting of H and C₁₋₃ alkyl wherein the C₁₋₃ alkylgroup may be optionally substituted with 1 to 3 halogens; A is selectedfrom the group consisting of (a) a 4 to 8 membered monocyclicheterocyclic group containing one nitrogen atom and optionallycontaining one additional heteroatom selected from N, S, S(O)₂ and O,and (b) a 6 to 10 membered multicyclic heterocyclic group containing onenitrogen atom and optionally containing one additional heteroatomselected from N, S, S(O)₂ and, O, wherein L is linked to a carbon atomin A and A is optionally substituted with 1 to 3 R^(k) groups; eachR^(k) is independently selected from the group consisting of F, CN, C₁₋₃alkoxy, and C₁₋₃ alkyl, wherein the C₁₋₃ alkyl group may be optionallysubstituted with OH, OMe or 1 to 3 halogens; R¹ is selected from thegroup consisting of:

wherein R^(p) and R^(q) are each independently selected from the groupconsisting of H, C₃₋₅ cycloalkyl and C₁₋₆ alkyl; R² is selected from thegroup consisting of H, Cl, OMe, Me and F; R³ is selected from the groupconsisting of H, Me, Et, CF₃, OMe, and F; R⁴ is selected from the groupconsisting of H, Me, OMe, Cl, and F; and R⁵ is selected from the groupconsisting of H, Me, Et, and F, to the skin of the mammal.
 39. A methodof treating cutaneous T-cell lymphoma in a mammal, the method comprisingapplying a pharmaceutical composition comprising a compound of formula(I):

or a pharmaceutically acceptable salt thereof, wherein X¹ and X² areeach independently selected from N and CH;

is selected from the group consisting of

R^(a), R^(b), R^(c), and R^(f) are each independently selected from thegroup consisting of H and C₁₋₃ alkyl; R^(d), R^(c), R^(g), R^(h), R^(i),R^(j), R^(l), R^(m), R^(n) and R^(o) are each independently selectedfrom the group consisting of H and C₁₋₃ alkyl wherein the C₁₋₃ alkylgroup may be optionally substituted with 1 to 3 halogens; A is selectedfrom the group consisting of (a) a 4 to 8 membered monocyclicheterocyclic group containing one nitrogen atom and optionallycontaining one additional heteroatom selected from N, S, S(O)₂ and O,and (b) a 6 to 10 membered multicyclic heterocyclic group containing onenitrogen atom and optionally containing one additional heteroatomselected from N, S, S(O)₂ and O, wherein L is linked to a carbon atom inA and A is optionally substituted with 1 to 3 R^(k) groups; each R^(k)is independently selected from the group consisting of F, CN, C₁₋₃alkoxy, and C₁₋₃ alkyl, wherein the C₁₋₃ alkyl group may be optionallysubstituted with OH, OMe or 1 to 3 halogens; R¹ is selected from thegroup consisting of:

wherein R^(p) and R^(q) are each independently selected from the groupconsisting of H, C₃₋₅ cycloalkyl and C₁₋₆ alkyl; R² is selected from thegroup consisting of H, Cl, OMe, Me and F: R³ is selected from the groupconsisting of H, Me, Et, CF₃, OMe, and F; R⁴ is selected from the groupconsisting of H, Me, OMe, Cl, and F; and R⁵ is selected from the groupconsisting of H, Me, Et, and F, to the skin of the mammal.
 40. Themethod of claim 33, wherein the compound is a compound of Formula (IV):

or a pharmaceutically acceptable salt thereof.
 41. The method of claim40, wherein the compound is selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.
 42. The method of claim41, wherein the compound has the Formula:

or a pharmaceutically acceptable salt thereof.
 43. The method of claim34, wherein the compound is a compound of Formula (IV):

or a pharmaceutically acceptable salt thereof.
 44. The method of claim43, wherein the compound is selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.
 45. The method of claim44, wherein the compound has the Formula:

or a pharmaceutically acceptable salt thereof.
 46. The method of claim37, wherein the compound is a compound of Formula (IV):

or a pharmaceutically acceptable salt thereof.
 47. The method of claim46, wherein the compound is selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.
 48. The method of claim47, wherein the compound has the Formula:

or a pharmaceutically acceptable salt thereof.
 49. The method of claim38, wherein the inflammatory skin disease is atopic dermatitis.